A tag, according to Wikipedia, is “a (relevant) keyword or term associated with or assigned to a piece of information (e.g. a picture, article, or video clip), thus describing the item and enabling keyword-based classification of information.” More simply put (with due credit to Flickr.com): tags are like keyword or category labels, and they can help visitors find items which have something in common.

With tagging, items are cataloged and organized by keyword. Those keywords can then be displayed as navigation using what’s called a “tag cloud.” In a tag cloud, the font size of each keyword is proportionate to the number of times that keyword has been used as a tag. In other words, the more items a tag has been associated with, the larger the font size. Tag clouds were first popularized on Flickr, the photo sharing website. The social bookmarking site del.icio.us further popularized tag clouds (see example below). A tag cloud provides web visitors with a quick visual indication of what tags are most popular on a site. It’s a new, more intuitive way to navigate an extensive collection of content and find information. A tag cloud makes your website look very Web 2.0ish (if that’s a word?).

Clicking on a tag in a tag cloud leads the visitor to a “tag page.” A tag page contains a collection of the most recent items that have been tagged with the particular keyword (see example below). Tag clouds aren’t the only way to navigate to a tag page. Typically, an item’s tags will be displayed adjacent to the item, with each tag linking to its tag page. Also, once on a tag page, you can often find links to other tag pages through a list of “Related tags.” A tag is related to another tag if there are items that that have the tag in common.

Tagging isn’t just a tool for usability (even though it’s typically mostly thought of in those terms), it’s also a powerful weapon for search engine optimization. That’s because tagging allows you to rejig your internal hierarchical linking structure, flowing the link juice more strategically throughout your site. And because those links are textual and keyword-rich, a tag cloud is far superior in terms of SEO to the traditional graphical navigation bar.

When tagging is applied to a website, such as a blog, it can significantly increase the site’s traffic by achieving visibility for a much larger array of search terms. Consider, for example, the case of my own personal blog, StephanSpencer.com: simply by tagging one of my posts with the keyword “blog optimization,” I received a top 10 ranking in Google for the query “blog optimization” — within only a few weeks and without any additional effort. It was a tag page that achieved the high ranking for me, and it was created automatically the first time I used the tag. (Note: I use WordPress, which now, as of version 2.3, has tagging built in.) A tag page, by its very nature, is designed to have its tag as its keyword focus. So, simply select a relevant keyword to rank for when coming up with tags for your content, and presto! — instant rankings.

Tagging is particularly effective at delivering Long Tail search traffic when the site offers “tag conjunction pages.” Although the various obscure Long Tail search terms may be searched on by only a few people, in aggregate, they can really add up to a sizable amount of traffic. Tag conjunction pages are created automatically by the fact that there are multiple posts with two tags in common. On my blog, the links to tag conjunction pages are displayed in the right column of my tag pages underneath the section “Related Tags” (see my “blog optimization” tag page for an example). You will see that each “Related tag” is preceded with an “AND” and an “OR” link pointing to a tag conjunction page. By displaying links not just to the related tag pages but also to conjunctions between related tags, multitudes more pages are made available to the search engine spiders.

It should be noted that tagging is applicable not just to blogs, but all types of sites — ecommerce sites, content sites, even corporate sites. Probably the most well-known ecommerce site is Amazon.com, and it supports tagging. In fact it supports consumer-generated tagging.

Some sites allow tags to be defined by the community of visitors, not just the content author. Allowing your visitors to create the taxonomy of content items on your site by tagging your content (this is known as a “folksonomy”) may or may not be a good thing. It depends on how good of a job your visitors will do and how good your quality control systems are at stamping out spam and minimizing noise. Amazon.com’s tagging system has been plagued with useless tags like “betty’s birthday,” which really only has value for the tagger and no one else. Nonetheless, tagging seems to be working for Amazon; if it wasn’t, they would cease expanding upon their tagging functionality and probably discontinue offering it altogether. Another issue with letting visitors do the tagging is lack of consistency. Sometimes visitors will misspell words, sometimes they will add hyphenation, sometimes they will use obscure synonyms. Which brings me to another point: your visitors don’t know how to (and don’t care to) conduct keyword research — identifying popularity of various keywords by search engine users. They may, for instance, tag a product with “hard disk” when “hard drive” is the much more popular keyword with searchers. But what do you expect? After all, you’re getting free labor!

One corporate site where tagging has been utilized, to great effect, is my company’s website, — Netconcepts.com. Tagging was largely responsible for a more than doubling of pageviews — within two months. First, every testimonial, every portfolio entry, every press mention, as well as each bio, article, and case study, was broken out into a separate blog post. Then, each post was tagged with appropriate keywords. For example, all the testimonials were tagged with the word “Testimonials.” So instead of having a single testimonials page as we used to, we have a testimonials tag page that spans three web pages (at 10 posts per page) and each of the 30 testimonials is a separate web page now too. In other words, we went from 1 page to 33 pages; that’s a lot more search engine fodder, all with different keyword foci!

Spiders can find and index these tag pages through the text links contained within the tag cloud on the home page, through text links underneath each post, and through links to “Related Tags” on each tag page. Remember, Related Tags are determined from posts that have the tag (from the tag page in question) in common. So, for example, because we have posts that are tagged with both “Web Marketing” and “Testimonials,” “Web Marketing” then appears as a related tag on the Testimonials tag page and “Testimonials” appears as a related tag on the Web Marketing tag page. Let’s restate that a little bit differently just to clarify… All our web marketing related items (testimonials, case studies, etc.) were tagged with “Web Marketing.” Consequently, there is a tag page that relates to “Web Marketing” and a tag page that relates to “Testimonials.” Additionally, there’s a tag page that relates to “Web marketing testimonials” — the intersection of those two tags. That makes for a plethora of tag pages, considering how many different permutations there are for various combinations of tags being “ANDed” or “ORed” together. The result? Thousands of tag pages and tag conjunction pages indexed by Google, many of which are bringing in traffic, albeit individually in small amounts. For example, a tag conjunction page ranks well in Google for “web marketing testimonials,” though few search for that term. In all, the traffic increase from this initiative was substantial, as illustrated in the traffic graphs in the case study at www.netconcepts.com/netconcepts-case-study/.

Over time, look for tagging to become much more widespread across the Web. Until then, tagging presents a distinct competitive advantage, both in terms of search engine visibility and user experience.

The Blogoscoped mention of Yahoo’s love for Flickr content is particularly timely, since Yahoo! announced back in June that they were permanently shutting down Yahoo! Photos in favor of their Flickr property, and the final closing date is tomorrow, September 20th.

Previously, I’d railed a bit against Yahoo! because I’d seen a lot of evidence that they didn’t spider/index Flickr content as well or comprehensively as Google did — altogether ironic since Yahoo owns Flickr. Just as with the anecdotal reports in the Blogoscoped post, I’m seeing nice indications that my earlier criticism of Yahoo’s lack of inclusion of Flickr content may now be completely resolved.

For instance, for experimentation purposes, I optimized a number of pictures of the picturesque Holly Hill House on Catalina Island via Flickr over a year ago. For many months, none of those pictures were showing up at all in Yahoo’s Image Search results (while, they were indexed and ranking really well in Google Image Search results within just a few weeks). Now, TWELVE of my Holly Hill House pics are appearing in the first 20 image search results on Yahoo:

(click to enlarge)

So, I’d say there is now even more benefit to optimizing through Flickr, since there’s greater chance of getting search referrals from Yahoo! Image Search results.

So far, I’m not actually seeing more referral traffic from Yahoo because of this, though, but I’ll soon be deploying much larger sample sets for the purposes of experimentation, and I’ll circle back around to report my statistical findings.

I can still critique Yahoo! a bit, though: images newly uploaded to Flickr seem to still have a significant amount of time before they get included in Yahoo Image Search results. Why? These images show up really rapidly via search in Flickr, so one assumes Yahoo would be able to pull those contents into their SERPs through a federated search of Flickr… The images really should be available quicker, and Yahoo should improve absorption of new Flickr images content faster.

Despite my griping, they rolled it out anyway with this feature unchanged, and they made it impossible to view the data through the old UI as of July 19th. They report adding more requested features, but how about adding back some of the functionality they destroyed? Perhaps they’re more involved in getting the daily data processing issues resolved, and admittedly I’d agree that would surely be a higher priority. I’m just still flummoxed because it seems so unnecessary to revoke good functionality in the first place.

I’ve found yet another irritating change that I consider to be even more serious: you apparently can’t view the data in monthly units - only daily:

(click to enlarge)

Why did they revoke the ability to visually compare monthly periods?!? Most search marketers I know like to compare overall figures from month to month since it tends to reduce some of the spikiness of short-term bursts, and lots of folks are using monthly billing cycles and such.

If I’m mistaken and there’s some where to set the period to display monthly, I hope someone will let me know. I hunted and hunted, and checked their help section to no avail. If they really did revoke monthly display, I can only reiterate further how bad this so-called “upgrade” really was! All glitz with little beneficial substance.

The Analytics team should borrow some of the members of the Google Maps team, since comparatively the Maps team seems to get it right a lot more lately.

AJAX is short for Asynchronous JavaScript and Extensible Markup Language. Make no mistake about it — JavaScript and XML are not “new” technologies. Both programming models have been around for some time. However, the unique combination of JavaScript and XML is relatively recent, as are the problems AJAX presents for a site’s search engine visibility.

The primary benefit of developing a site with AJAX is the ability to work invisibly in the background of a site. AJAX is used to supply data to the client browser that renders up as a relatively seamless “application” instead of the click-and-wait-to-load functionality associated with more conventional web page constructs.

How seamless is the user experience with AJAX? Check out Google Maps or Google Suggest to see world-class AJAX applications in motion. You can find what you want, when you want it, with relative ease and accuracy when AJAX is in use. What you can’t find is a unique URL or navigational links for search engine spiders to crawl and index, which brings us to our first SEO barrier to overcome — the “J” in AJAX.

JavaScript has been a stumbling block for search engine visibility for quite some time. None of the major search engines show any indication of overcoming these types of scripted data issues anytime soon. Consequently, the single greatest optimization issue with AJAX is the tendency to not generate unique, bookmarkable, linkable and therefore indexable URLs.

The comparative shopping engine Become.com overcomes this barrier by creating and linking together static URLs of search results pages. A quick [site:www.become.com] search in Google reveals how well this AJAX-workaround in indexed.

Meanwhile, sites like Scion.com fail to make the same programmatic leap to provide a similar search experience. Imagine how the carmaker could promote celebrity built custom automobiles in the search engines if only static pages of a punked-out Ashton Kutcher or a blinged-out Usher-mobile were rendered and linked to throughout the site.

While AJAX can be a great way to enhance the user experience, not all visitors will have a great on-site experience when non-JavaScript-enabled browsers are being used. When it comes to site accessibility and SEO, it’s imperative that an AJAX-alternate experience be provided.

Because AJAX relies on JavaScript — as well as Cascading Style Sheets (CSS) and XML – it’s relatively easy to provide an alternate experience for non-JavaScript users. The key is to tap into your CSS and XML files to render other versions of the AJAX application. This tactic is as “progressive enhancement.”

Progressive enhancement is a web design strategy that emphasizes accessibility, semantic markup, external style sheet, and scripting technologies. By layering designs in a concatenated progressive enhancement allows all users – and search engine spiders – to access the basic content and functionality of any web page.

When implementing progressive enhancement, a basic markup document is created, geared toward the lowest common denominator of browser software functionality. The web designer then adds functionality or enhancements to the presentation and behavior of the page using CSS, JavaScript or other combinations of Flash or Java applets. In tandem with user-agent detection, progressive enhancement will automatically render both user- and search engine-friendly pages.

You can observe progressive enhancement in motion by visiting Amazon’s Create Your Own Ring page. Simply turn off your JavaScript capabilities to see how the program maintains its AJAX-like functionality for all users. Also note that the initial load of the AJAX application contains the optimized elements such as title attributes, header tags and meta description, as well as a crawlable static URL. All of this is visible in Google cache and revealed in the page’s search engine snippet:

Amazon.com: Create Your Own Ring: Diamond Search
The Amazon.com Collection. Why Buy Jewelry & Watches at Amazon?
… More to Explore. Preset Engagement Rings … Create Your Own Ring …
www.amazon.com/gp/cyo/cyor-fork.html

To produce these particular SEO elements, server side scripts and .htaccess rewrite modules are required. (If site is not Apache server-based then the rewrite module may not be an option, but there are always solutions.)

When optimizing AJAX it’s important to remember three things: Search engine results are affected by on-the-page, behind-the-page and off-the-page factors. It’s essential to provide an alternate way for users and spiders to navigate their way through to all of your great content without sacrificing usability, accessibility and linkability.