[newaccount74]

I try to follow this as much as possible, but at some point when providing a paid service you run into the problem that you need to track whether the user has paid for the software or not.

So even though my software does not require user accounts, it requires a serial number to activate all features. That serial number can be linked to the purchaser, so in theory my app could do really invasive tracking. (It doesn't, but my users have to rely on my word)

How can one fix this? I would love for my software to somehow anonymously check whether the user paid for it, and isn't running it on more than X devices, but I'm not sure how this could be done without revealing the users identity.

[13415]

Mullvad allows Bitcoin purchases of tokens, which can then be used as a serial for the VPN that works for the time period you've purchased. Users can change tokens any time. That's probably close to what you're already doing.

[lucb1e]

Or for those less blockchain-inclined, you can just send them cash as well...

https://mullvad.net/en/pricing/ ctrl+f cash (the section has no anchor)

[trs-80]

Yep, came here to say this.

It doesn't get any more anonymous than cash in the mail. :)

[newaccount74]

I'm not sure how Mullvad does it, but I keep a record of who purchased what serial number. My number one customer support request is people asking for their serial numbers because they lost them, which is why I keep a record.