Here's my opinion without any credentials attached:
* Free tier - essential
* Documentation - essential
* Stack overflow tag - desirable
* Free tier - essential
* Documentation - essential
* Stack overflow tag - desirable
I experimented with a "pay as you go" plan that starts at $0 and includes some free PDFs, but so far I've earned close $0 from all of these customers. But this might just be because the people who asked about alternative pricing are much more price-sensitive and early-stage, while bigger companies don't think twice about $49/mo.
For a new product would you think it odd if there was a load of questions and answers by the company - faqs sort of thing?
It would be a monitored tag so questions would get answered
Geocod.io has a free tier and we used it at work until we bought the full thing. Google Cloud has a trial and I activated it and then didn't use it so I didn't actually get to try it.
So not quite equivalent, I suppose, since the lock-in is tighter with free tier. You never put anything critical on trial but you do on free tier.
I much prefer when the trial counts down some other finite resource that I have some control over, rather than wall time. For desktop software, number of days of actual use are a good option, for SaaS that's often difficult to measure sensibly. (Was the app open in a background tab somewhere? Oops, time's up.) So I'm much more likely to give a trial period with a fixed number of events/tickets/jobs/whatever a go.
Some things, Money can't buy. For everything else there's... :P