Cooperation is one of the most powerful secrets to Internet success. Rather than attempting to be a specialist in every aspect of your special area of expertise share the limelight with others. In business it's often better to be a key player on a minor league team than a bench warmer on a major league team. If your product is not the best it's more profitable to sell someone else's product than lose the sale or lose the trust of your customer. In the long run it's more profitable to grow a customer for life than to make a sale that isn't the best long-term solution for your customer.
Successful businesses depend on satisfied return customers.
When someone gets a referral from a source they trust it's much easier to make the sale. I give testimonials whenever I find a product I can recommend. It turns out that I get at least as many referrals from others as I give out. Much of my income comes from referrals from so-called competitors, many just returning a favor. Many successful Internet marketers are doing business in this manner on-line.