HitsBoosterPro is a free manual traffic exchange, where you receive hits to your sites in return for visiting other members' sites.
It's a very simple system. All you have to do is sign up and start surfing by clicking the link in the members area. You need to spend at least 6 seconds on each site to receive credits, and every 10 credits you earn are worth one visitor to your site. You receive 500 free credits just for signing up, and surfing the 25 sites needed to fully activate your account. You can also earn extra credits by referring other members.
There is a choice of different membership options. When you first join, you will be given a free new member platinum upgrade, which will last 7 days. After that, your account will revert to free status. You can keep your free account for as long as you want. (If you are an active surfer, you can earn lots of traffic this way, and it won't cost you anything.) If you have less time to surf, or you simply want to earn more credits, there are 3 upgrade levels available. Upgrade your account to Silver, Gold or Platinum, and you will earn more credits per site view than free members, more referral credits, monthly bonus credits, plus commission on referral upgrades and purchases. Gold and Platinum members also receive random referrals. (There is more information on the different account types inside the members area.)
There are also options to buy extra credits, if you need more than you can earn through surfing.
To find out more, or to join right away, check out the links at the side of the page.