I am in vendor changing process right now. To be exact it started at christmas last year, as i needed a vendor with a gift purchasing and networking ability. I took than a commonly used system. But it is known to be laggy, so i choosed another one last week, also a vending system in commonly use. For politeness I'll not say which systems that are: It is stil temporary, the final system will come somewhen next month.
Well, what about the updaters now
The standalone vendors i used all the time ran a simple update server. A sold product box runs a script which is able to send a valide update request. The server inside the vendor receives the request and gives out the update. Who bought a procuct gets easilly an update for it. Even at any other vendor. Simple and reasonable.
A networking vendor system has an advantage: you can flexibelly install the vendors whereever you want or even give out as afillate vendors. But keeping update servers inside the vendors is than no more possible. After first system change (that one last year) i installed also update servers additionally into the vendors. Last week as i replaced them, i simply forgot to reinstall the update servers. Sorry for that.
However, i am thinking about improving the update system, keeping it compatible to old one, making it easier to use and easier to maintain: Briefly saying, it will be networking too. More detais follow as soon it is developed and i am ready to push the red button.
For now, there is a single update server. I called it "Updateruby" and installed on Sadenia. That is the locatoin of the first vendor i provided in the notecards inside the product boxes, so i think it is no needs to update them yet. The SLURL is this: