Zipidee founder and CEO Henry Wong says that the most important thing an entrepreneur needs to know is that "startups need cash all the time."

That means startup CEOs should think of themselves as a "cash extraction officer" and should be talking to customers and investors all the time about how to bring more of the green stuff into their company.

Those who don't understand that concept are "destined to fail," says Wong, who says he learned that lesson during the dotcom bust when his B-to-C company, like so many others, became "a miserable failure."

Taking his own advice that a startup CEO needs to be "doggedly optimistic," Wong is working for a different result with Zipidee, which sells instructional audio and video files online. Last month, the San Francisco-based firm acquired TotalVid for an undisclosed amount, thereby doubling to 10,000 the number of titles that it owns exclusive online rights to.

Wong's last piece of advice is to attack markets that are so big and fast-moving that they allow some room for error.

Last month, Zipidee was a winner in the SDForum business plan competition on Vator.tv. To see the pitch that impressed the judges, click here.