Boost is an easy to produce search ad designed to show up when someone does a related search. Own a Chinese restaurant in San Francisco? Then your ad might show up at the top of the page when someone searches for the best Kung Pao Chicken in the Bay Area. Google develops the pay-per-click ad from a short description supplied by the business owner and all of this is done using the dashboard in their Google Places account.
“Placement in the “Sponsored Links” section of the page will, as always, depend on factors such as your ad’s relevance and quality. Boost does not affect the ranking of the free, organic business listings in any way.”