Takes a lot of cash for Gabe to have a bath in I guess...

Not quite.

They actually don't distribute the biggest selling PC game of the last 5 years ( world of warcraft) and won't distribute the best selling game of 2009 ( Starcraft 2).

No, but they have 70% share of all PC digital downloads, so in that respect, they have a monopoly on digital downloads (assuming Starcraft 2 is disc based).

You can purchase Wow through digital download

Monopoly means exclusive or 100%.  However, I understand that some people use it as slang for 90%+.  You are likely looking for different slang as you are just referring to an estimation of 70% market share.  That same estimation includes another company as having 10%, which completely destroys your monopoly theory.

Actually, a Monopoly is when a company has so much control over the Market that it can disregard the prices and quantity that other companies provide, since the comany itself determines the market price, because of it's size. That's the economical definition. A monopoly can only exits on a market with entry barrier or blocks, since in an open market, the tendency is to competitors come until the monopoly is over. I reckon Steam is a monopoly given brand recognition, since most people who Download legal games know steam, and goes there first for games, reinforcing the company market power.

As such, Steam is not a monopoly. It must set a price equal to or less (and often less at least for short periods) than the retail store price. All other online retailers are locked into this same price.

Steam is a special case, since highest price is determined by industry and quantity is limitless, but apart from that, they set the DD price level given brand recognition. You´ll probably never find nowhere more expensive then Steam because they just wouldn´t sell, simple like that.

No.  A monopoly is when you hold a bunch of land next to each other, build really expensive rental properties and then force anyone who stands still outside of them for a few minutes to rent the house for a day at gunpoint.

That's another definition...