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.
BuySellAds - BuySellAds.com Online Advertising Network
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.
Media.net - Yahoo! Bing Network Contextual Ads powered by Media. net gives you instantaneous access to one of the world's largest marketplaces for advertisers. People also askWhat is Media Net?What is Medianet Cisco?
AdBrite - Looking for AdBrite? | SiteScout
AdHitz - Lets you sell ad space on your site. You choose the details and then paste the code to your site.