This. Absolutely agree with both points. Going it alone is hard, and developers have issues with self promotion. Sales seems like dirty word to us. The thing is, when I'm the customer, I don't mind being sold to. As long as it's not a flat out lie, I actually find I appreciate the stuff I buy more if the sales person made me feel good about it.
I have a friend that is like he's born for being in sales. He loves money and have almost no moral qualms when it comes to selling (but paradoxically have a heart of gold when it comes to charity and being nice to people).
Some people actually enjoy making lofty promises for money. I guess that's part of why being in a team is a good idea.