Kontera

Kontera works in a similar way to Infolinks above, however, they have been around for much longer. Traditionally it was hard to get accepted by Kontera but they seem to have relaxed their restrictions of late. This is especially true for website publishers and affiliate marketers that do not have high daily page impressions.
Kontera is extremely easy to use. You simply add a few lines of code to the end of your webpage and within 24 hours additionally links start showing up on your page that serve Kontera Ads. While this service does not provide you with a complete replacement for all your ads, since they do not provide banner creatives etc., it does provide an additional way to increase the revenue your site can generate. The links are context sensitive and relevant so click through ratios can be very high for well designed sites.

Some of the features offered by Kontera:
• The best payout in the business.
• Premium ads with market-leading CPC.
• Record high CTRs.
• The best relevancy and user experience.
• Works within your text � no extra space required.
• Takes only a minute to set up.

Kontera is nice because it is simply Plug and Play and it provides an additional revenue stream for your website. It does not require any additional space or layout considerations since it integrated directly with your text. In my opinion the inline text ads also look smarter than a lot of other offerings.
In May 2011 Kontera started rolling out additional features designed to maximize revenue and value for publishers. These represent extensions of what Kontera do today and are intended to deliver better revenue and value publishers. The Retargeting offering is part of Kontera's Audience Program and leverages their unique ability to understand and assess user interest via a semantic engine designed to yield greater revenues for publishers. Kontera's Retargeting presents a unique opportunity for publishers to earn additional revenues from Kontera ads that they already serve. Kontera finds interested consumers on publisher sites and qualifies their interest by leveraging their Synapse technology. When they see these users elsewhere on the web they show them relevant banners and share the revenues with the publisher where the user first expressed interest.
The value add for the publisher includes:

1) Additional revenue (approximately 10-20% more on average once the entire Audience Program is fully operational)
2) No technical requirements
3) No change to user experience
4) Ability to participate in an exciting and novel growth area in advertising