The reasons are many which I'll list base on my situation:
1. It allows me to purchase stuff through online means (which I couldn't before due to the country I'm in).
2. The fee is little to nothing as compared to other options out there
3. Fast and easily could send money to someone other than my country (normal ways, I had to go through 2 banks in order to complete these kinds of transactions)
4. Pseudonymity
5. No government in control of it
6. No restriction on who uses it
I really agree with you when it comes to having been allowed to purchase some stuffs online globally. Not only that, the fee itself is really little compared to other peer-to-peer technology. That is why I am using bitcoin because of the benefits that I get from it.