Best benchmark: Get a paying customer who isn't in your inner circle of friends or family. If you can hit that benchmark, it means you've literally knocked out laundry list of other obstacles that many startup blogs will outline.

If you can't achieve that, then analyze why and there's where you put your effort. If you need money to hit that mark, then you better be a good pitch person or have previous track record - otherwise, you're fighting an uphill battle.