I believe Steam themselves holds promotions every so often where they release games for lower prices and sometimes free for a limited times. There are also some places that give out codes for free downloads that are given to them by steam as a promotion. Nintendo, Microsoft, and Sony do this as well.... So.. It is possible.. My best suggestion however is to look on the internet for revievs for this particular site and see if there are any complaints against them.
I would suggest only trusting well known sites that you know are legitamite or only use the Steam official site and sales if you are really looking for deals.
Last edited by dcj91x on Tue Feb 05, 2013 12:45 pm; edited 1 time in total