That is, a person clicks regarding your ad from an ad network maybe a , you pay a specific price or bid.
If this does not work, you can be honest and say in regards real price you is able to afford. http://Haibao.Dlssyht.Com.cn/index.php?c=scene&a=link&id=302927&url=http://Forum.altaycoins.com/viewtopic.php%3Fid=1137793