Notifications are a bit of a problem with web apps. It's much easier to do everything client side on a mobile device and I haven't figured out how to elegantly implement a notification system on the server side. I could potentially do everything by email but that brings a whole bunch of other headaches with it if I don't want to be blacklisted as a spammer. Currently I'm looking at appcelerator and adobe air to make the app more accessible to a wider audience but that's a little ways away.
That would be fine if I had a server sitting somewhere constantly checking for prices. Currently I just push all the code that would be processed on the server onto the client. I'm not expecting to get millions of users but I'm also not interested in managing my own server. Making the whole process decentralized and getting the application on the phone to manage itself is a much better solution. There is no equivalent way to do that for a web app. No matter what I will need some kind of central location for people to push and pull their alerts from if I make a web app and there are plenty of services like that already.
That's interesting, so you don't have a server at all? Does that mean you don't collect any usage data? That's key to improving your product and building new ones.
