Venture Capitalists, How do you approach the challenge of assessing the long-term sustainability of a startup's product or service?

As a recruiter who works regularly with new companies, I've often offered advice to early investors of the firm. That's because I'm surveying a well-informed sampling of candidates through the hiring process and, as a result, have unique insights into the long-term success of the business. There is a direct correlation between ease of hiring and future results. A company that attracts top talent will also be a strong contender in the marketplace. In fact, applicants can often be seen as a test audience.