The chrome web store is great, but comparing to the Android market place or the Apple app store, it's almost negligible. Why? Are there less people using web? Or are there less web app developers? Obviously neither of those are true. What Google really should do about the chrome web store is to focus on the supply side and make it as much like the mobile app eco-systems as possible.
One of the major reasons mobile app stores exploded is that there is minimum cost to deliver an innovative idea into a product immediately available to the mass, (well at least for those ideas that does not require a centralized service). All you need to do is to write the code. There is minimum infrastructure needed at your side to create and distribute the product. Your revenue management is also taken care of. You can almost completely focus on your code. I think this is the key to innovation explosion on mobile platforms.
For the web apps, things are a lot more complicated. Writing the code is arguably more enjoyable than the mobile app. (RoR vs Objective-C or Swing like Java), but then you also need to do 3 things
1) get a server infrastructure and setup the environment.
2) create a store front - either put it on the chrome web store or maintain your own marketing website which is harder to get mass attention.
3) setup your revenue flow because your server infrastructure is going to cost you money. you can either embed some ads service, or you can create a subscription system and integrate with some 3rd party online payment service.
None of these 3 things are trivial. They make innovation on the web platform significantly harder than on the mobile platform.
Being a web adds company, Google is probably the only company that has the incentive and resource to push for an innovation explosion on the web platform. I am proposing that Google should create a web app platform with integrated infrastructure/marketing/revenue services. Let product developers focus on product development and this platform takes care the rest:
1) an elastic and flexible cloud computing platform that is optimized for web app deployment. Technological wise, though, there should be as less limitations as possible. It should be more like EC2 less like app engine.
2) Google already has this - the chrome web store. Make it more prominent rather than just a chrome browser/os concept.
3) A revenue sharing system to cover the cost of the cloud computing. To conform to Google's free service for ads revenue philosophy, this revenue sharing system is probably ads based. It can start from a single limited cloud computing resource (like the free EC2 micro instance.) Once the usage volume and the ads revenue increase to a certain level, higher tier of resource will be 'unlocked' for the product to allow even larger usage volume and ads revenue.
The idea is that there should be a minimum entrance cost to this web market just like the Android market and Apple app store. People can just create prototype product of their innovative ideas and throw it to the market to test the reaction. How exciting that will be.