Free trial versus freemium. If you have a larger base (free tier), even if a small percentage upgrade to paid, then you may make more money. It's what Dropbox and Slack do.
But Dropbox has always offered the free option.
Nylas used to have a free plan, but at some point took it away entirely -which actually meant cutting away a part of their base.
I feel like they might change their mind again and remove the free plan.
> We already sync several hundred terabytes of data for our users and are adding tens of thousands of new users each month. It’s costing us real dollars.
This is now changed with the new architecture in Nylas Mail.