In July, Bloomberg BusinessWeek reported that Microsoft also, made a serious attempt to acquire business directory and reviews site "Yelp". According to "two people involved in the negotiations", the Redmond software giant even bid as high as $700 million for the company. But, Yelp opted to remain independent."
Now, on December 16, 2010, a U.S. federal trademark registration was filed for "POSTBOX", by Microsoft in the category of "Advertising, Business & Retail Services".
The description provided to the USPTO for POSTBOX is:
"on-line business directories featuring restaurants, bars, nightclubs, tourist attractions, entertainment and sports events, seasonal and holiday events; and providing online information concerning restaurants, bars, nightclubs, tourist attractions, entertainment and sports events, seasonal and holiday events".
The USPTO has given the POSTBOX trademark serial number of 85200057.
If you put the above two together, it appears that Microsoft's plotting an online local business and events directory that invites users to submit information about those businesses, i.e. reviews, rankings and the like.