What you will get with those kinds of offers is tracking cookies, at a minimum. They track what sites you go to, your freinds, the things you buy, etc. Then, they sell that information so that you can be targeted with ads on things the advertisers think you will buy. But, if you buy from Amazon, they already know what kinds of things you buy. If you have free virus protection, they know. If you do Facebook, they know (or twitter, instagram or pinterest).
At a maximum, you will get some kind of "spamware" that will show you pop-up ads. You will then have to reinstall your browser to get rid of it.
A commercial site like that will generally not give you a virus. They want to make money on you, not make you afraid of them. If they were handing out viruses, the word would get around quickly. Their investment in their site would be lost quickly.
bkay