Mid-December, CBS will remove its inventory from most – though not all- ad networks, giving rise to a fire stoked two years ago warning publishers against reselling to third party sellers, which saw ESPN, Weather.com and National Frontier, amidst other publishers, terminating business with ad networks.

Now major publishers are searching for ways to open their own ad networks- systems which monetize by buying ads at the lowest costs and then adding data and enriching the same – and selling them at much higher prices.

Although these flourished in past decades when publishers came up with a surfeit of ads than they could possibly profitably sell- disgruntled publishers unhappy with dismal ad rates across the web are slowly distancing themselves from ad networks, CBS being the largest of them to do so, focussing solely on systems such as Yahoo’s Right Media Click, Google’s Double Click and Publicis Group’s Vivaki’s Virtual Audience, and holding back its inventory from networks with non-aligned data.

The recession led a foray into the world of ad networking by publishers- who now, with the gradual resurgence of the economy- are willing to sacrifice small incremental revenues with larger ones brought in with a more prospering fiscal ambience- made on a one to one platform.

Nonetheless, the marketplace for ad networks is expanding with markets preferring to make contact with networks than with a wide orbit of publishers.

The CBS strategy is not likely to impact markets as largely as the Yahoo follow up on its promise to renege networks from its Right Media Exchange.

Time Inc has debarred all ad networks except corporate sibling ad.com.