Avi Levine is the executive director of the Digital Professional Institute (DPI), a Chicago-based programming and digital marketing school, affiliated with Tribeca Flashpoint College. He has more than 10 years of experience growing successful business, including PhilterIt. Follow him at @avidpi.

Who’s your hero? (In business, life, or both.)

Bob Dylan.

What’s the single best piece of business advice that helped shape who you are as an entrepreneur today, and why?

Take action. As an entrepreneur, you’re constantly grappling with uncertainty. The worst thing to do is let that paralyze you. Instead, get into the habit of taking decisive action. Move forward continuously, relentlessly and with discipline.

What’s the biggest mistake you ever made in your business, and what did you learn from it that others can learn from too?

Just one!? One of the biggest mistakes I’ve made is not having a deep appreciation for true customer needs. If you don’t fully understand the customer, you can’t reach them successfully.

What do you do during the first hour of your business day and why?

I make sure to knock at least one thing off my to-do list to generate momentum for the day and notch an early win.

What’s your best financial/cash-flow related tip for entrepreneurs just getting started?

If you can sell early and bring in cash, sell early and bring in cash. Otherwise, there are endless hacks out there to get around expensive upfront investments.

Quick: What’s ONE thing you recommend ALL aspiring or current entrepreneurs do right now to take their biz to the next level?

Get comfortable with selling and understanding the metrics that drives sales.

What’s your definition of success? How will you know when you’ve finally “succeeded” in your business?

My vision of success is creating happy customers who tell other customers about what our products do for them.