Online news site TechCrunch reports that "multiple sources" have confirmed that Yelp and Google are in an advanced stage of negotiations over a possible purchase of the former, a user reviews site for local businesses.

Search engine optimization (SEO) experts have already compared the prospective deal to the one that brought YouTube under Google’s wing, in that both YouTube and Yelp are thriving online communities with huge user bases that could be more easily targeted with Google-based SEO, should the deal come to pass.

Other analysts, like Greg Sterling at Search Engine Land, say that the move could spell trouble for many of Google’s current local marketing partners, who would be displaced by Yelp’s long-standing online community and extensive content offerings. Additionally, Sterling writes that Yelp could be used as what he describes as an "onramp" to Google’s Local Listing ads, which are scheduled to reappear sometime in 2010.

Yelp is already partially integrated with Google, using the search giant’s mapping features to localize content, provide directions, and display geographically-weighted data.