LeanMarket's value proposition is probably not very clear to anyone who isn't familiar with real-time bidding. This Google whitepaper goes over the industry at a high level: http://static.googleusercontent.com/external_content/untrust...

One core component of RTB is the separation of supply and demand. This is different than the ad network model where a central hub connects the buyers and sellers who all work with the network. This "central hub" approach is true of AdWords; you can buy traffic from AdSense publishers through AdWords and no one else.

Through LeanMarket, you can buy impressions from publishers who sell through Google, Microsoft, Admeld, Rubicon, or PubMatic--none of whom LeanMarket has a direct relationship with.