Well, there's attribution, non-commercial, and share-alike. there's about 6 combinations, and 3 versions of the licenses. That's 18 licenses. Let's say 30 countries, and you get close to that figure: 6*3*30 = 540.
Bandwidth/storage/electricity (if they have their own datacenter).
Unfortunately, Wikipedia has an inefficient architecture, they could save money if they, for instance, didn't use MediaWiki (although that would be very difficult to achieve)
It has a web browser, local and global WiFi multiplayer. But they don't want to employ anyone to maintain their online services and keep them pedo-free.
For Hotmail you can use Microsoft's own offline client, "Windows Live Mail", which is the successor to Vista's Windows Mail (and therefore Outlook Express), or use Outlook.
Indeed. SMS costs nothing to the carrier, apart from operating the transmitter.
It was initially free, but became so popular they decided to commerically exploit it.
Indeed. I do a lot on this PC with an Intel "Pentium Dual-Core" - basically a C2D with less cache.
I write software, play games, IRC chat, make videos. I regularly have 20 apps open at once.
My PC rarely slows down or freezes.