eBay is planning to launch a contextual/keyword based ad network called eBay AdContext.  Imagine Google Adsense, but with all the ads being for eBay auctions relating to the content of the page the user is viewing.

So, will this gain traction?

I think it will.  For two reasons:

1.  In order to make contextual advertising work, you need to have a lot of ads across a lot of topics.  Adsense has been a success because Google has such a huge advertising base to draw from, primarily advertisers looking to get on Google search results.  Yahoo Publisher Network and other contextual ad networks have had trouble providing great results for publishers due to not having enough ad variety to cover so many topics.  eBay has auction listings for just about everything, so they could probably provide relevant auction ads no matter what the topic.  A caveat though, I think for some sites it doesn’t make sense to be advertising things that can be bought via auction, Adsense does provide more variety with advertisers selling products and services.

2. eBay already has a big and successful affiliate program so they’re used to helping web publishers make money off of their listings.

This could be a winner if eBay executes it right and provides more revenue for publishers. That’s really the bottom line.