This is a repost of my response to a question on UWebD list, but since the list doesn’t have publicly available archives, I thought it would be valuable to post this here.
In my opinion, marking up content with microformats falls right in the stride of any Web standards-aware developer, because the reasoning behind microformats is exactly the same as the reasoning behind supporting Web standards.
You don’t support Web standards to get a W3C badge or earn respect of colleagues. Even further, you don’t support standards to improve accessibility (although accessibility plays into standards). You support standards because you want your content to be correctly interpreted by the widest audience possible.
And since interpretation of content relies on semantics of markup, the notion of semantic markup plays an important role in this goal. Microformats are but a way of extending semantics of HTML in a standards-compliant fashion, through a well-thought-out process.
Even if you aren’t a Web standards believer just yet, you should use microformats in the context of search engine optimization. I believe… strike that, I know that Technorati’s microformats search, released a few weeks ago, is the tipping point for widespread adoption of microformats crawling by search engines.
Rather than relying on obscure and fuzzy techniques of determining the purpose of content, the capability to accurately and cheaply extract specific types of information (such as contact info, event info, reviews, etc.) it’s a no-brainer value proposition.
Besides, microformats are very easy to add to the page. I did this at a couple of my presentations — ask the audience to give me a page and convert contact information into a hCard within minutes.
Now, speaking of the big boys. Who’s on first? Well, Yahoo! Although Bill Gates did mumble “we need microformats“, reacting to O’Reilly’s pressure at Mix’06, it is Yahoo! Local beta that went live yesterday, featuring over 17 million pieces of microformatted content.
When we started this a year ago, this was just a crazy idea. Now it’s becoming clear that it’s something that might just make the Web a better place.