The post comes off really condescending towards the beta users that helped get the product off the ground.
Sure, the business lessons are valid and helpful (despite being a complete regurgitation of advice espoused by people like Rob Walling and Patrick McKenzie), but IMO they don't belong in the same post that tells a cohort of your very first users:
"Yeah, we needed you in the beginning to test our idea and product, but now you're a burden. Get lost."
Grandfather your free plan beta customers in. It's the right thing to do. The free plan, IIRC, had a really low ceiling in the amount of data that could be collected--like 150 people or something silly.
Lessons for SaaS founders: 1.) Don't have a free plan. 2.) Don't set an expectation that there will be a free plan to get more early testers. 3.) Don't ever refer to any of your customers (free or not) like they're a number in a spreadsheet.
(Is it just me, or is the trak.io blog theme eerily similar to Signal v. Noise?)