What are some alternatives?
Google AdSense - Use Google AdSense to make money online by placing ads on your website and YouTube channel. Start monetizing your website with Google AdSense today.
Infolinks - Discover what Infolinks smart ads can do for you
Smart AdServer - The only fully-integrated ad server for managing RTB, Mobile, Video & Web display. Best manage all your campaigns in one interface. Best local support
BuySellAds - BuySellAds.com Online Advertising Network
OpenX - Ad technology platform available as a hosted service or as an open source download.
Clicksor - Promote your business with today's most effective contextual online advertising and re-targeting technology and behavioral Marketing Services at a cost effective metric of CPC, PPC, CPM or CPV.