I'm writing a live auction app sort of like proxibid.com. When an item goes on the auction block how would I updated the server if there are no clients connected to drive the app? Lets say an item goes up for auction at 10am. There's nobody in the auction room to bid on the item so 10 seconds later I need to notify the server and flag said item as unsold. Any incite would be great.
Backends are a potential solution. You could run a permanent backend, keeping track of and marking unsold. https://developers.google.com/appengine/docs/python/backends/ . These may be a better solution than cron.