Google is the undisputed king of this, taking their core business and releasing products that are very different, but still tie back to the mothership by serving the little gold nuggets that are adsense ads. I think Adobe is doing something similar. Up until yesterday, they had been releasing concept applications that showcased their Flex 2 technology. NoteTag, which I talked about on ReadWrite/Web, was the most significant, but it required you to download and run the code on your own server. A hosted version was supposed to be forthcoming, but hasn't appeared yet.
JamJar is another story entirely. Described as the "Anti-MySpace" [pdf], it has the stated goal of filling a need for "shared paper" on the Internet. It allows for users to set up "spaces" and share files, information, and photos within those spaces. In very Google-esque fashion, the application serves up AdSense and has an invite feature. It also does a good job of showing off Adobe's technologies, specifically the real-time collaboration aspect of the Flex 2 line. Mike Potter has a good run down of why JamJar is Adobe's "First Web 2.0 Application".
But how does it tie back to what Adobe does best; shrink-wrapped software? Right now, the picture is cloudy. It showcases the technology, it's making some money off of Adsense, and it gets people to download FlashPlayer 9, but those don't really tie back to Adobe's core business. Here's what I think: Much like Google, Adobe will continue to release these hosted applications. In order to drive adoption of their core products, Adobe will open up these web applications so that Flex developers can tie into them and create widgets or addons. In theory, Adobe can provide a large infrastructure, with significant user base, and people can buy Flex Builder to create content and tie ins for these hosted services.
It drives adoption of Flex Builder, it showcases the technology, and it makes Adobe a player in the web application space. They won't aim for the "web office" like Google seems to be doing, but they do have a huge head start in the collaboration world, and JamJar shows how they can take advantage of that. Make no mistake, this is a test run, but there have to be minds at Adobe thinking way beyond this test run and seeing Google as a good company to emulate.