Yahoo and Yelp recently partnered allowing Yelp reviews to be shown on Yahoo Local Business Listings.
Sounds fair enough. But it seems they made a bit of a pigs ear of the implementation and instead off allowing for previously generated Yahoo reviews, and combining them with Yelp ones, businesses have simply lost any previous Yahoo reviews. Something that will also happen on Bing, as Yahoo and Bing have a content partnership deal.
Local Businesses Losing Reviews After Yelp-Yahoo Deal - Search Engine Land
"We partnered with Yelp, one of the most trusted, relevant sources of consumer business reviews, to provide a richer search experience for Yahoo users. That’s why when Yelp’s reviews are available for U.S. businesses, they will replace Yahoo Local reviews."
So if you had 25 reviews on Yahoo, and then get 1 on Yelp, you lose the previous 25
Be interesting to see if this is rolled out to the UK, as Yelp has a much less dominant position than it does in the UK. But it does seem a very odd way of doing things, and with access to all that technical resource, they certainly could have done it better IMHO!