Kontera is a in-text PPC ad network which has been launched few years ago. This is one the most popular in-text ad networks which provides you PPC ads. There are fix feelings among publishers about Kontera. There are many who complain about low rates which some others say they are happy about what they earn from Kontera. Also if your CTR is good you can contact them for fixed CPM rates. Kontera is better for sites which receive loads of traffic. You can earn money online with Konera even by using their ads along with AdSense ads.

One Good thin about Kontera is they offer lot of good Resources for publishers, such as, Kontera now offers Blogger users a one-click implementation widget for their blogs, Their Wordpress plugin offers maximum flexibility and ease when implementing Kontera In-Text ads on WordPress blogs and also there are plugins for Joomla and Drupal. You can still earn money with Kontera by using it properly with other ad networks.

They have a referral system too but not every publisher friendly. The members of Kontera's Affiliate Program has to be Kontera publishers who meet 3 requirements: Publisher has run Kontera ads for at least 3 months, Publisher revenue is $100 or more each month, Publisher is in good standing with Kontera. So I don't think it's easy earn money from Kontera Affiliate program.