Notes about the Mac App Version vs the standard version
Old way (Kagi)
The old method is not going away. The app store is only for 10.6.6, and there are a lot of users on 10.5 and even 10.4. The 10.4 version will be discontinued this summer, but 10.5 will be supported for a few more years. The app store also at this point does not support volume discounts. It might in the future, and it would be great if Apple implemented that. But for those reasons, and prime among them the 10.5 support, the kagi license mechanism will stay.
Updates
Updates will be done using both methods. In fact 2.3.1 is out and is in the review pipeline for the App store. It was submitted Jan 7th. Hopefully it will not take a long time to be approved. And I’m sure that review process will speed up once the initial crunch is over. The app store update mechanism is very slick, but the current update mechanism lets you know of a new version as soon as you launch DataGraph.
Trial
You can download a trial version (download here) and then buy DataGraph using the app store or from within the application. Because of a quirk in the app store, if you have DataGraph on your machine it says that it is Installed and you can’t purchase it. There isn’t a simple way to overwrite that in the app store (for example by clicking on the menu) and hopefully they will add that in a future version. Right now what you have to do is to remove all versions of DataGraph and then go to the App store. If you run the trial from a disk image this will happen as soon as you unmount the volume.
Beta version
You can still use the beta version after you have purchased through the Mac App Store. Download the beta from the same link as everyone else. And run it without restrictions. The way this works is that the App store version leaves a registration key that the beta version uses to make sure that it is registered. This registration key expires in a couple of months, so you need to periodically run the Mac App store version. Just launch it and quit. This also means that in order to use it on a different machine you need to be able to use the Mac App store version on that machine.
Buying
Currently the Mac App store will indicate that DataGraph is installed when you are running an unlicensed version downloaded from here.
If you want to buy from the Mac App store, what you need to do is to remove all copies of DataGraph from your disk, and then relaunch the Mac App store. Then you can purchase it.
If you have any other questions, please send feedback (Help menu.) I will update this page as needed.