You need to make money somehow. Google Search has its monetization model aligned perfectly with its primary purpose: You visit Google.com to find something. Getting to that something may be sponsored, it may not be. Your click on a sponsored link is perfectly aligned with what you set out to do. Compare this to MySpace where you go to interact with friends but are assaulted by ad banners trying to divert you. As a user I prefer the former, meaning your revenue features should be aligned with the purpose of your product.