Ad blindness is a problem that a lot of webmasters struggle with. The problem is that many visitors do not notice the ads on your site, and because of this your PPC earnings might never be high. Ads help to pay the hosting fees and that is why many webmasters decide to implement them on their site. The key is to do it in a smart way. First of all, it is better to have few ads and they should be targeted at your particular niche. Secondly, it is crucial to place them in a place where they will be visible by your visitors, but at the same time they should not be intrusive.