We have technology, finally, that for the first time in human history allows people to really maintain rich connections with much larger numbers of people.
You should pursue your passion. If you're passionate about something and you work hard, then I think you'll be successful. If you start a business because you think you're going to make a lot of money at it, then you probably won't be successful, because that's the wrong reason to start a business. You have to really believe in what you're doing, be passionate enough about it so that you will put in the hours and hard work that it takes to actually succeed there, and then you'll be successful.
eBay's business is based on enabling someone to do business with another person, and to do that, they first have to develop some measure of trust, either in the other person or the system.
When I started eBay, it was a hobby, an experiment to see if people could use the Internet to be empowered through access to an efficient market. I actually wasn't thinking about it in terms of a social impact. It was really about helping people connect around a sphere of interest so they could do business.
Don't let people who you may respect and who you believe know what they're talking about, don't let them tell you it can't be done because often they will tell you it can't be done, and it's just because they don't have the courage to try.