I decided to search for my local pizza place on google. I got a fairly good hit via their google+ listing, but their actual website was missing.
The node that I'd tagged myself is fairly well described, and I ended up updating both Google mapmaker and OSM.
It occurs to me that even if we're not trying to compete with google in the local business listings, it would be interesting if we could build on it. If I've mapped an area, I want others to benefit from the data I've created.
Take for example, amenity=restaurant.
We know about 350,000+ of them:
325 659 have names. 150 598 have cusines. 44 900 have websites. 36 416 have phones.
Imagine if we were to change
... when we had enough authoritive data.
Google Rich Snippets (https://support.google.com/webmasters/answer/99170?hl=en) are just one of the benefits - schema.org, with RDFa would enable OSM to very quickly join the linkeddata (http://linkeddata.org/) web, and possibly provide a real world application or two in doing so (as compared to http://linkedgeodata.org/ which is great, but I've never used as an end consumer for example).