This module allows members to bid on ad placement position to appear higher in search results. Members setup their ads on the site and then buy a credit balance of funds (called a reserve). The advertiser then assigns a "bid amount" to each ad they setup. Advertisers can setup as many ads as they like. The bid amount determines the placement of the ad when displayed with other ads in a listing. The higher the bid amount, the closer to the top of the page the ad appears. Each time sponsored ad is clicked (from unique IP to prevent spam clicks) on from the search page, the bid amount is deducted (debited) from advertiser credits. When the reserve drops below a particular amount set by the advertiser, an email is sent out as a reminder that they need to add more credits to their reserve pool.