There should be a way the person who asks the question can send $10 by Paypal to the person who answers the question without disclosing email. The site has the email, so just enable a button to send the equivalent of a six pack. Also, users who express such gratitude should be marked, so people who can answer questions will know they can get sth by answering the question.
As someone with lots of reputation and experience... This won't happen.
The purpose of the site is to ask people for free help, not to come here and expect to be compensated for their efforts.
It's great if you found an answer that was extra-helpful, or that you're willing to pay, but the way we say "Thanks" here is with upvotes, choosing the answer as the best, or bounties.