What are some alternatives?
Google Ad Manager - Grow revenue wherever your users are with an integrated ad management platform that surfaces insights for smarter business decisions.
Facebook Audience Network - Facebook Audience Network is designed to help monetize your apps and websites with ads from global Facebook advertisers.
OpenX - Ad technology platform available as a hosted service or as an open source download.
Taboola - Drive traffic to your site, blog or video, or monetize your site with the largest platform for content recommendation, audience acquisition, and native advertising.
AerServ - AerServ offers monetization solution for mobile publishers.
Written - Written helps content marketers build their audience by licensing content and audience from bloggers.