Founders are their own worst enemies when trying to find product market fit (PMF).

Here are the five worst mistakes:

1/Not being clear on the metrics for PMF.

It's not rocket science but you need to be clear.

2/Focusing on more than one metric at once.

Moving metrics through experiments requires creative thinking to try new things. Trying to move two at once kills this. Take a few weeks focusing on your top priority, then focus on another even if you haven't hit your goal.

3/Believing that experiments are optional.

Many founders think they know the answer and just need to execute on their vision. But even the best experimenters are wrong 80% of the time. My best teams run 5 experiments per week every week all the way through Series A and beyond.

4/Being too lazy to measure.

When you are trying to understand your user's behavior and emotions, it just doesn't work if you don't measure correctly. Use mixpanel and get your attribution on new users right early.