What's the appropriate way using desktop like notifications in a webapp (chrome notification feature)

Question

I'm planning to use Chrome's notifications feature. I want to show important informations on the notifications. My "users" are highly qualified technical persons, so i think it's good idea.
But not so many webapps using this stuff.

Is it ok to use or not?
Do you know any good examples to use the notifications?
On what cases do you use?
How to make notifications on the mobile version?

Update
Chrome notification
Here's how it looks like

Answer 1

Chrome's notification system works best when combined with extensions and Web Store installable or hosted web apps. When a user installs an extension or web app, they are asked once whether they want to give the app certain permissions, such as local storage, location, or desktop notifications. Once they give that permission, it's permanent until the app is uninstalled again.

So you should consider that when you design for Chrome notifications. The best use case is when you're launching an app in the Web Store, as you'll have a 100% guarantee that your audience will be able to benefit from the feature.

One of the most valuable reasons to have Chrome notifications is to add value as an application. You can use background processing to pay attention to something in the background even if the user doesn't currently have your app loaded, and then pop up a notification to alert the user. If your app has behaviour that takes a while to execute, that's a great way to tell the user some task has completed. Or you can let them know when they receive a new message, for example.

In fact, Google recommends using these features to offer a "rich experience". From Google's "Thinking in Web Apps" design principles for Web Store applications:

Rich experience

A web app offers a rich, engaging experience for the user that is indistinguishable from native desktop applications.

Apps typically should meet or exceed users' expectations of how functional a web app can be. Web apps should use and exploit features, visual clues, and interaction paradigms previously found only in desktop applications.

For example, using modern techniques and browsers, web apps can offer desktop notifications, geolocation, beautiful typography, drag-and-drop, high quality graphics, and more. They can use cross-origin resource sharing to consume content from remote sites, and they can use WebSocket to show live content and support real-time communication across the web. Ideally, the user forgets about the browser and focuses solely on the application.

Answer 2

Just going off of a gut feeling I would avoid using Chrome's Webkit desktop notification. Going beyond the gut feeling I can give these reasons why I would choose to build a notification system inside my web app as opposed to using the webkit one. These being:

1. It only works in Chrome. Unless you know for certain that every one of your users is going to be using Chrome -or- you only care that those users get notifications, this is a bad idea. Alternately you will have to develop a notification system for all of us who don't use Chrome and then, depending on what browser I am in, deliver the notification one way or another.
2. I have to agree to it. Unless I am familiar with your site I am not going to agree and your notifications will not make it to me. If you use an in-page notifications I will at least get your notifications when I am on your page.
3. If I have agreed, I will get your notifications when I don't have your page(tab) focused. I think this is confusing, could be spoofed by other sites, and leaves me with a bad taste in my mouth.

All in all I think that notifications that are in place on sites like this one (shows when you get a badge or whatever) and others get the job done well while being modeless and non-intrusive (see this SE post). I would probably follow that lead and do something similar to accomplish this without, at the very lease, being browser dependent.