Lukas Mathis has posted some thoughts on the issues Mac newcomers have with .dmg files. I also talked about this issue a while back in a post on the most common issues switchers have, but it’s worth noting it again. I agree with his followup post that adding another file format isn’t really the way to go either – DMG files are a great feature to have – once you’ve understood them. But from a usability and customer support perspective, a simple zip file seems to be the better choice.
I’d still be interested to see what kinds of customer support issues you run into with zip files though:
But despite those questions, I think there is a valid reason to reconsider whether .dmg files should still be considered “best practise” for app distribution.