Name the three types of bidding available to advertisers in an ad network.
1.) CPC Bidding (Cost per click)- The advertiser only pays when the displayed ad is clicked, which means the advertiser pays only when the ad brings a visitor to the website. So if an advertiser pays $0.50 CPC, and an ad yields 50 clicks, the advertiser would owe $25 regardless whether the ad was shown 1,000 times or 100,000 times.
2.) CPM Bidding (Cost per mile) -the payment method of traditional advertising. If a magazine charges $20 CPM for a full-page advertisement and it has a circulation of 250,000, an advertiser would have to pay $5000 for a full page ad in the magazine ($20 times 250)
3.) CPA Bidding (cost-per-acquisition)-enables advertisers to pay only when their advertisements result in successful conversions. If a website sells flags, and the advertiser bid $10 CPA, she would owe $10 every time an ad led to a flag purchase on her website. So if her ads led to 10 purchases, she would owe $100 regardless of whether those ads brought 100 or 1,000 visitors to her website