The Search Engine Unfriendliness of Web 2.0

Wouldn't it be great if all those whiz-bang Web 2.0 interactive elements
based on AJAX (Asynchronous JavaScript and XML) and Flash -- such as
widgets and gadgets and Google Maps mashups -- were search engine
optimal? Unfortunately, that's not the case. In fact, these
technologies are inherently unfriendly to search engine spiders. So,
if you intend to harness Web 2.0 technologies for wider syndication,
increased conversion, improved usability and greater customer engagement,
you'd better read on or you'll end up missing the boat when it comes
to better search engine rankings. When it comes to AJAX and Flash, the
onus is on you to render them search engine friendly. The major search
engines just can't cope with these Web 2.0 technologies very well at
all. Some search engines, including Google, have rudimentary means of
extracting content and links from Flash. Nonetheless, any content or
navigation embedded within Flash will, at best, rank poorly in
comparison to a static, HTML-based counterpart, and at worst, not
even make it into the search engine's index. Google's view on Flash
is that it doesn't provide a user-friendly experience. Flash is wholly
inaccessible to the vision-impaired, unrenderable on devices such as
mobile phones and PDAs, and can't be accessed without broadband
connectivity. In particular, Google frowns on navigational elements
presented exclusively in Flash. Given this stance, Google isn't likely
to make big improvements on how it crawls, indexes and ranks Flash
files anytime soon. So, it's in your hands to either replace those
Flash elements with a more accessible alternative like CSS/DHTML or
to employ a Web design approach known as "progressive enhancement...
AJAX poses similar problems to spiders as Flash does because AJAX
also relies on JavaScript. Search engine spiders can't execute
JavaScript commands. AJAX can be used to pull data seamlessly in
the background onto an already loaded Web page, sparing the user
from the "click-and-wait" frustrations associated with more
conventional Web sites, but the additional content that's pulled in
via AJAX is invisible to the spiders unless it's preloaded into the
page's HTML and simply hidden from the user via CSS. Here, progressive
enhancement renders a non-JavaScript version of the AJAX application
for spiders and JavaScript-incapable browsers. A low-tech alternative
to progressive enhancement is to place an HTML version of your AJAX
application within noscript tags.