Here's this report that Rick Bruner has been working on (He now holds the jazzy title of Director of Research at DoubleClick) - The Decade in Online Advertising.

So, what is the current state of online advertising? The three conclusions that can be drawn from the report are -

1. A seller?s market is emerging in online advertising. - The law of Supply and Demand is finally coming into play in Online Advertising. Earlier the segments like auto, tech and business, which were buyer?s market are turning into a seller?s market.

2. Marketers are demanding more accountability. - Now that internet advertising is no longer Terra Incognito, advertisers are demanding greater accountability from publishers for the return they get on their advertising spending.

3. Consumers are demanding more control. - Consumers are demanding more and more control over what the media feeds them rather than the other way round, which has been the traditional case till now with TV and other mass media.

A few more findings from the report -

a. Search advertising has the Lion's share of the online ad spending.
b. Roughly half of online buyers make a related search before their purchase.
c. More media revenue now comes directly from consumers than from advertisers.

Read the whole report here - Landing Page. PDF. It's pretty interesting.