Some advice that can be useful for software sales too:
It’s much easier to just borrow other peoples’ audiences when you need them.
Try emailing prominent bloggers discount codes for your software — you then can borrow their audience if they are willing to publish your discount codes just like the linked articles says (for getting “beta” users).
Interesting article on Mixergy with suggestions from other entrepreneurs on how to find an idea for a new startup. What stood out for me was this:
Run some cheap tests
Though this only applies once you have an idea, I thought it was an excellent suggestion on using Google AdWords to run ads based on your idea to see if there is some interest in the idea.
Some information on merchant accounts and some follow-up information regarding getting a credit-card processor.
Yet another discussion on Payment Processing. This time on Hacker News. Some focus on subscription billing. Got to see some names I haven’t seen before — Braintree, Spreedly, Cybersource, PowerPay…