If you own a website then your ultimate goal has to be for it to receive as much traffic as possible. After all:

No Customers = No Sales = No Money

Broadly speaking, there are two ways in which to bring traffic to your site and at no cost.

Auto Traffic Exchanges, such as Autohits are the easiest option. Your site is shown to thousands of users, 7 days a week, 24 hours a day, and all you have to do is sign up and keep a browser window open which will rotate members websites and earn you turns in this rotation. Whilst there is no doubt that this brings lots of traffic it is unlikely that most traffic exchange users will actually view, or take any notice of your site whilst it is rotated.

Manual Traffic Exchanges, Clickthru and WebmasterQuest, for example, have remove the automation by requesting users to either rate sites or click on a specific graphic after a specified period of time has elapsed, forcing its users to view the web sites in the rotation. How much value these sites have in respect of quality traffic, however, is arguable. That said, Clickthru and WebmasterQuest are well worth a visit as they both offer many, many other addition functions and means to drive traffic to your site.