comparing apples and oranges. google has way more expenses than the coffee shop next door, but that doesn't mean it's harder for google to earn a profit.

my personal opinion is that facebook users on the whole are a lot more engaged than twitter users. i know an awful lot of folks on twitter who use it as a broadcast medium rather than a place for conversation and connection. facebook seems to be a place where people actually connect with each other more. granted, this is all anecdotal.