I wouldn't say "blows them away", but apparently, customer service is generally bad enough that these things often provoke a pleasantly surprised reaction: 1.

I wouldn't say "blows them away", but apparently, customer service is generally bad enough that these things often provoke a pleasantly surprised reaction: 1. Make it clear that solving their problem is paramount. Not your policies, not getting off the phone ASAP. Sometimes it's something you can help them with directly with your product, sometimes you can't, but just treating them like a person you want to help instead of someone to hang up on is apparently unusual. (This is also a good fit for a lot of the techie folks on HN.) 2. Send a handwritten note. My handwriting is terrible, practically illegible, but people like that I took the time to write to them with pen & paper. Ironically, I didn't do this for a long time, because I thought it would look cheesy, but I gave it a shot and realized I like the little bit of gratitude it brings into my day-- that's really why I do it.