Every major piece of social software got off the ground by "spamming a bunch of people." But it was different spam. And the gradations do matter because they're orders of magnitude better and orders of magnitude less load on the system.
speak for yourself. I really have no wish to play in spamish "grey areas"
Being an Entrepreneur does not mean you need to abandon your sense of right and wrong, or your respect for your fellow man. I don't know about you, but this isn't the first company I've started, and it won't be the last. Damaging my own personal reputation in exchange for some more success at this one business is probably a bad idea, long term, especially when the business is one that only works as long as you stay 'under the radar' (meaning, it doesn't scale, because the facebook spam people would stop you.)