If you knew with 100% certainty that your oil well would strike black gold, then you'd be better off borrowing the money to start it up, knowing full well that you could pay off the loan and keep all the future profits to yourself. But since most businesses are very risky ventures, especially new ones, you should take on equity partners instead (or consider crowdfunding sites like Kickstarter). That way, if things don't pan out, you won't be on the hook for the start-up costs and you can move on to the next venture without debt hanging over you like a cloud.