The forum has many discussions about trust and reputation. Perhaps it would be useful if CoinPal buyers could choose to make their purchase history available as one demonstration that they're trustworthy. I currently do this by rating customers in #bitcoin-otc when asked. However, some people don't use IRC and may want their trust broadcast in another way. Consider this a solicitation of ideas for ways to broadcast that trust.
Someone suggested that CoinPal could automatically sign a customer's PGP key after a successful transaction. I know very little of PGP's best practices. Is this a good idea? Can such signatures be revoked if a customer charges back after the initial signature?
How about providing customers with a "letter of recommendation" URL which they could share with others? This URL would display a summary of the customer's purchases (date and BTC amount). Since the page would be served from CoinPal's site, a third-party could be confident of the document's authenticity and accuracy. If a customer charged back a payment, it'd be immediately reflected on the page. I suppose this "letter" could either be English text or a JSON document.
How about a PGP-signed "letter of recommendation"? It'd be similar to the above letter, but it would also have my PGP signature. That way, it would persist even if CoinPal crashes, dies or otherwise disappears.
I plan to continue supporting #bitcoin-otc's web of trust and improve CoinPal's interaction with it if people are interested. Thanks for any feedback.