Patrick McKenzie is the founder of Bingo Card Creator, a website that lets teachers print out bingo cards for their classes and Appointment Reminder, a site that sends out phone, text, and email reminders to clients for businesses.

When Patrick first started Bingo Card Creator, he had a day job with 19 hour workdays.  Today, he spends an average of 20 minutes a week on Bingo Card Creator and no longer has a day job.

In this interview, we discuss Patrick’s marketing techniques for his sites, his advice for entrepreneurs, and some lessons learned from a big mistake made building his company.