Monetizing a Twitter bot?
goodkarma: Four ideas:1. Are you getting their e-mail addresses?  You could send out some kind of e-mail once a month with a summary of their packages and some ads and/or affiliate offers.2. Since you are sending them direct messages, they must be following you. Use Magpie or some other service to just post advertisment tweets (not direct messages) to your public timeline. You get paid on a CPM basis.3. After every nth package, send them a DM asking for a donation if they appreciated the service.4. License your app to be the official Twitter bot of any of the package tracker services. So if someone tries to track a package on any of their sites it gives them the option to add to your twitterbot. (This one would be the hardest/most work, obviously.)