"...only 1% of them actually stick around and pay you for your product."
Those two quotes lead me to believe that you're not doing lifecycle emails. Would those people still forget after receiving four emails from you over the course of those 30 days with specific calls-to-action leading them back to the site? Would only 1% of them convert if you actually sent them an email asking them to come back to the site and enter their card details?
My experience has been a lot different to the author's. I see almost exactly 25% of my free trial customers converting to paid. And over half of those enter their card details on the day I send them an email asking them to.
So if you're not doing that, I could see you getting the results you were getting.
That said, it sounds like it would make for an interesting long-term A/B test. I'll try to get around to doing that, and if I do I'll be sure to post the results here.