Not sure what you mean? Each offer opens in a new tab and the homepage itself doesn't seem to hijack anything...
When I click through to visit the homepage, clicking the back button just once does absolutely nothing. I have to click the back button several times per second in order to actually move back from the site. Sadly, in my experience, such website behavior is becoming gradually less uncommon.
I think you have something wrong with your browser -- I tried in both Firefox Nightly and Chrome Dev and I don't have this problem on two different computers.
I'm using Chrome 29.0.1547.66m on Win7 x64. I'll try it on my home computers tonight (one of which is running Ubuntu 13.04).
Now, that is odd...I just tried the page on my Ubuntu system, and the back button wasn't hijacked at all.
All links on that page open in new tabs for me (Chrome 29.0.1547.65)
For me, the homepage refreshes twice and lists 3 links in the back history.