AOL's Platform-A marks its foray in the online ad exchange space with BidPlace, a self-service marketplace exchange with an eye toward helping marketers better manage display campaigns, reports MediaBuyerPlanner.

BidPlace launches in the first half of next year. The marketplace lets advertisers bid for CPM, CPC and CPA ads on AOL, across other partner sites, and across Platform-A's third party network, according to Platform-A.

Platform-A pres Lynda Clarizio says the difference between BidPlace and other online ad exchanges, like Yahoo's Right Media Exchange, is the power of the AdLearn optimizer, which AOL acquired when it purchased Advertising.com in 2004.

Marketers running a CPA campaign can use a simple set of tags and use AdLearn to pinpoint the best places to run media to meet a specific ROI, without having to compute each place individually. "With other exchanges, you can bid on inventory, which is a fantastic thing for an advertiser, but how do you know that you have the algorithmic intelligence to bid on the right places?" Clarizio says (via paidContent).

A la carte ad exchange ADSDAQ offers a similar capability. The technology "machine-reads" millions of content pages in real-time to deduce their context, so ads appear in alongside text that supports their message.

Partner and senior internet analyst William Morrison of ThinkPanmure says the online ad exchange marketplace is now a $1.1 to $1.2 billion market.