Meebo, which provides web-based instant-messaging, is now building an ad network around those chats.

The meebo ad network will release an API that allows publishing partners within chats on their sites. meebo is positioning this as a custom-built product.

Chatroom hosts that prefer an ad-free environment will also have the option of paying a licensing fee to keep advertisers out.

Ads will be targeted based on demographic and geographic data, culled during the registration process.

Blog publishers may soon feature IM chats that extend posts in a manner similar to comments, but with the conversational feel of instant messaging. This may present opportunities for vendors able to provide real-time comment quality control.