Firstly, because it's relevant to what most of us are doing here.

More importantly, because all advice I've ever been given on this subject by mentors is to always ask for credit card up front in your app, unless you have compelling objective data to justify waiving that requirement.

Especially if you're doing B2B SaaS, for example, a good "default" best practice has in the past been to ask for the card up front to ensure quality trial users. And I've always shared that advice with people just starting out.

5 years ago, I could point out dozens and dozens of web apps asking for card, up-front, even if those apps offered a free trial. It used to be, the exception to this rule were funded companies, or large, established industry players, because they had large war chests of cash and could afford to take risks with their trial-to-paid funnel.

Seems like this has really changed, and maybe the accepted wisdom should be updated to reflect this new trend.

I still believe that it's better for your trial-to-paid conversion stats to ask for card up front, and yes this comes at the expense of a lower free-to-paid conversion rate. But I still believe its worth it, especially for a bootstrapped B2B startup.