This summer, Google plans to launch a revamped version of the ad exchange it picked up in tandem with its acquisition of DoubleClick last year.

Ad exchanges, which operate somewhat like the stock exchange for online ads, enable publishers to auction ad space to ad agencies. Yahoo and Microsoft already run their own ad exchanges; what's more, both have a large lead over Google in terms of display ad dominance, in part because they can place ads on their own content pages, such as Yahoo Finance and MSN Money, BusinessWeek points out.

But Google believes it can close the gap fast, placing ads on sites like its popular YouTube destination as well as on partner sites, including The New York Times and a broad array of blogs.

Google and DoubleClick's ad-placement systems use different software, forcing clients to jury-rig a unified monitoring and ad-buying system between them. In the offering that debuts this summer, both systems will be integrated, improving the ad buying experience. And with more pricing and bid control, Google is encouraging web publishers to avail more space to their exchange.

Agencies and advertisers will also be incentivized to ensure their ads are relevant to users. When ad space with price and audience demographics match the ones advertisers have set for a given piece of creative, the spot will be able to run instantly.

These changes all come with the hope that display ads will feel accessible, even to the smallest of businesses. It also hopes to compel larger websites — which control most display ad revenues — to join the exchange.

In January, AdSense and DoubleClick accounted for 57% of total ad server market share. Rivals Microsoft and Yahoo lost significant share at the time.

Mid-April witnessed the launch of DoubleClick Network Builder, a tool that enables publishers to develop and maintain their own networks — a small step toward stimulating the space and making it more accessible to gun-shy advertisers.