Smart advertisers will continue their move toward retargeting and behavioral targeting and will probably look to make better use of video ads, which offer an as-yet-untapped potential to capture consumer attention and drive home messages with the same power that TV has long provided.

Advertisers will also need to be smarter and more contextually relevant. "In the old days, you could simply advertise 'Drink Coke' and everybody would buy it," says Tas of Sportgenic. "But today, choice is so prevalent, it's critical to be able to understand who you're speaking to, and to speak differently to an urban kid versus a country club golfer and to tailor those messages. That's the direction the marketing world is moving."

Smart advertisers will also experiment more broadly to see what works best for them online. Does that vertical ad network reach the prospects we like? What's the best strategy to build our brand online? The best methods are likely to be different for every advertiser. In the absence of clear-cut guidelines, the key will be to roll out several new ideas and see what each one yields.

"You can make your clickthrough rates go up through more dancing monkeys and more scantily clad models and giving away free motorcycles," says Federated's Edwards. "That will always drive the metrics up. But you won't be optimizing toward a more effective brand execution. Brands need to move past thinking of the internet as solely a channel for acquisition, and see it as a place where customers are spending a lot of time, and start to think about putting brand marketing tools online, as well."

As a kind of test, more aggressive advertisers will probably want to allocate some of their online dollars to a wide range of networks. If one delivers better than most, more of the budget can be shifted in that direction. ROI is one key metric, of course, but when advertisers move beyond direct marketing campaigns, they'll need to consider overall reach and frequency, and even try to measure the offline lift they're getting from their online campaigns.

Conclusion
The fact of the matter is, ad networks are going away at about the same speed that publishers are learning how to sell every bit of their own inventory directly, which translates to: not very soon.

But that doesn't mean they'll get a free ride -- far from it. Today's online ad networks will have to cope with a variety of new forces in the market, and to survive, they almost certainly will have to morph into significantly more sophisticated business institutions.

Robert Moskowitz is a consultant and author.