Product market fit is not a clear or easy to define concept.
To find product market fit, you need to first read and understand Mark Andreessen's post on product market fit for startups.
To determine if you have product market fit, you need to measure customer adoption and growth, and hire additional staff.
Michael Seibel is a partner and the CEO of YC. He cofounded Justin.tv, which was in the winter 2007 batch and Socialcam, which was in the winter 2012 batch.
2:00 - Three types of people: people highly motivated when working for themselves, people that could succeed starting a startup or within a big company, and people that could succeed within a big company.
6:00 - How do you decide what type of person you are?
7:30 - Identify bias in advice givers
10:30 - Peer advice becomes less valuable during college