Credit: Mike Blumenthal
This apparently went out as an email promotion to businesses that had claimed their Places listings. The 30-day free offer was similarly part of the trial for the more ambitious and complex Local Listing Ads, which are apparently never to return.
Recently Google took out a full-page ad in the WashingtonPost aimed at small businesses. Taken all together these efforts reflect a more direct and aggressive push by Google to acquire traditional small business advertisers.