If the company is connected and a good enough reward to be hacked then it will be done.
If you have to be connected to the world, then may sure your target/reward is smaller than everyone else then they should get hit first.
Facebook would be a great target for businesses as most of their employees are glued to facebook and got to be hitting their productivity.
Yes, but Facebook has no financial gain with the possible exception of identity theft via social engineering.
Hacking a web site that accepts payments is much quicker ££££