Seems to me the public domain is pretty much tapped-out. Unless you're going to re-invent something old or turn it into an absolutely new product, there's little value in churning out the same "me-too" stuff and just flooding it into a new distribution channel (ebay, amazon, bonanza, sell.com, etc.). Once your buyers realize it's "public domain" material they get mad and feel like chumps because they could have googled and got it for FREE.
Has anyone here found a way to milk the public domain in a way that every other info marketing monkey ISN'T doing it? I'd be interesting in hearing, otherwise my conclusion is that the public domain is a complete and utter waste of time. What do you think?