I am not talking about Cost Per Click (CPC) to an advertiser. I am talking about the cost or the efforts associated with moving the mouse so that the mouse pointer rests on the link in a given web page.  Below is the very first page of now famous social networking site, mixi.jp, of Japan:
 
Despite of its all-by-invitation only membership, it has the “sign up” button, which, upon click, leads you to the following note:
The note basically is saying, among other things, “..we regret to inform you that, to sign up, you have to wait for someone to send you an invitation.” Personally, I’ve found this user interface quite disturbing, since i’d imagine that by clicking on “sign up” button in the previus page, any first-time visitor would have expected to become a member. Every time the expectation goes up, mixi turns it down.
People DO BOTHER to click on something in expectation of experiencing something else in the next page accordingly. So please do not betray them.