Dota 2 keys are all over SteamGifts like stink on a monkey!

Isn't it a bit awkward considering the OP's name? ;)

I hadn't noticed until you mentioned. I am simian-neutral!

It happens to the best of us ;)

Why did it happen to me, then?

It might seem quite obvious what DOTA is all about after a quick explanation, for anyone who has actually played DOTA, but it might be a tad bit hard to wrap your head around it if you have not seen the game in action. So check some gameplay videos of it (on youtube), and keep in mind that each player plays a single "character", and that teamwork is key in this game. There is actually a surprising amount of depth to these games, something that might not be apparent at first sight.
But also keep in mind that the communities that has formed around DOTA-style games are vile. Don't play with random people, play with friends or not at all.

That is a good point. Even if one likes DOTA and its likes, the communities that form around them are among the worst on the internet. THE WORST.

Ha ha! I asked this for the longest time.
Someone has even gifted me a DOTA 2 key and I'm still not quite sure what it is other than an online multiplayer only title that is meant to be a really polished and sophisticated RTS / RPG.

From what i understand it's going public and free 2 play towards the beginning of next year.

Invites were in heavy demand last year. I scored a copy of Skyrim in exchange for one.

It's an ASSFAG. Aeon of Strife Style Fortress Assault Game.
Aeon of Strife was a map for the original Starcraft, and was the primary inspiration for DOTA.

Yeah, I came in later on the offer and the gift I received was a key which I didn't want to risk getting stolen or getting claimed before I could trade it off so I just added it to my library.

I was already worried this gem wouldn't make it to first page.

Yeah, Awesomenauts is... awesome

That's a game :D