[yaur]

One of the major advantages of working through an agency is that they have processes in place to asses credit risk and handle collections.

This isn't limited to startups though. I've seen a medium sized company stonewall on payments until the freelancer in question was willing to settle for 20%-30% of the agreed upon price simply to recover something for the time they invested in the project. This was a negotiating tactic for them and when it didn't work they would pay whatever interest rate was agreed upon in the contract, which was often nothing.