Sales is the lifeblood of any company, here's an except from a post on the MBET Blog:

"the most interesting point was that successful companies had high levels of sales force productivity. So many people talk about success being based on technical excellence. To heck with that. Success is based on how hard you can sell your product. The rest of the stuff is important but never forget that a great company is more than just a R&D department."

My thoughts exactly, problems with your product, technology or customers are all serious issues, but none of them scare me. Sitting with a perfect product with great infrastructure to support it without a consistent sales flow does.