Software comes with no tech support, no backup CD, and no free upgrades to the next version of the program. Example: You download DoStuff 1.0 for free; when DoStuff 2.0 comes out, you don't get a free upgrade to it. Each offer literally lasts a day, so if you're late to the party. don't expect a piece of cake.
A wide variety of software is made available. I'm going to go out on a limb and say that you won't be interested in every day's selection, but if you find something appealing/useful/fun, you can save money. There's also a daily game giveaway. Don't get too excited; these are the kind of games that sell for $10-$15.
I recommend checking this out if "free" makes you tingle. This isn't a paid ad. It's just me, passing along a good thing to my friends--exactly the way Giveaway of the Day is supposed to work.