Clarity's terms of service state that:
"You (as a Seeker) may cancel an Appointment without penalty; provided, however, that you have not already initiated the call with the Expert via the Services. You (as an Expert) may cancel a scheduled Appointment without penalty at any time."
I personally think that if the cancellation is done up to about 3-4 hours before, then it's reasonable not to charge, but anything less than that should come with a partial cancellation fee. I personally spend anywhere from 10-30 minutes preparing for a call in order to promise the most value for the caller. I don't expect to be paid for this time, but if the caller doesn't cancel and just doesn't show, there should be a cancellation fee. Alternatively, each user (including experts) should have 2 'no-shows' after which they get blocked.
If it gives you any comfort, I know that the caller's 'Clarity Score' is negatively effected.

Hell no! Don't be petty.

Sucks when this happens. I think two things. One, make sure we're not doing this to others....be our own best client. Life just reflecting actions and reactions from our past. Two, could Clarity charge a 10% deposit to lock in the call which gives the power to reschedule if a client can't make it and if they don't reschedule they lose the deposit?

Good luck on trying to collect on that one.

While I understand your frustration at this situation I wouldn’t expect to be compensated for services I had not yet provided. Maybe something happened beyond the prospect’s control. Think medical or emergency. We should also remember while we are here providing value without the clients paying the fees this platform doesn’t exist. Hopefully the next call goes much better for you!!

I think a deposit requirement would be NICE via Clarity... however, that would also reduce the overall number of conversions. So... just roll the dice and if someone skips a meeting, make sure to take that hour and do something productive for your OWN business ;)

My rule.

They get one strike, then I bill a retainer for any future calls at a minimum of $1000 (10 hours credit, towards calls or work).

In other words, they get 1x strike, then they have to pay up front.

Same for any slow pay invoices.

People who pay quick, get a Monday invoice for past weeks work.

People I have to chase for money, must pay a retainer for all future calls or work.

Note: I run a private hosting company, so clients who pay slow also get a message on their site about their site being in maintenance mode.

So... Where possible, only do client calls or work, where you have some leverage over clients.

Tip: Of all the clients I've had since 1994 only one is on a retainer basis. He complains every time I tell him, his retainer is used up + he must pay again.

He complains. Then he pays. All's well...