What is Push?
Instead of "pulling" content from Web sites using your browser, with push technologies, you just "tune" your client software to receive information from a server site and sit back and drink in the content. It's like putting your Web browser on autopilot.
The difference between push and pull is a little like the difference between tv and paper magazines. You have to go out to buy the paper stuff (you have to "pull" it in). With tv, you just tune your client (tv set) to a site (television channel) and sit back on the couch and soak it in (content is "pushed" to you). Except push on the Net is a little different, perhaps more like television-on-demand, because you can sometimes request specific content without having to wait for it to be broadcast at a specific time.
What is the Big Deal About Push?
The idea is that users of push clients can get continuous feeds of content delivered automatically. Users can customize their push clients (this is the reason for characterizing push technologies as "narrowcasting"). The user thus receives information based on their interests at periodic time intervals or in response to some event.
The benefit of push is that the user doesn't have to go out and find items of interest--they instead tell a push client their interests, and that client acts like a receiving station which periodically asks push servers for information. Some push clients take advantage of the idle time on a users computer to do this data transfer, making it possible, for example, for users to get a whole Web site's pages and graphics downloaded for convenient, offline viewing.
The term "push technology" relates to a number of Internet-based communication application types including "Web broadcasting," "multicasting," "channels," and even "agent technology."
Who is Using Push?
An early push application was PointCast a news service which enjoyed a hype bubble in early 1997. With PointCast, you can create your own personal view of news content and receive regular updates.
Another push innovator is a company called Marimba. In Marimba's model, Castanet transmitters (servers with software and information) provide information to Castanet tuners (clients that query the servers). Users of the tuners can choose from a variety of content divided into channels. When new content on a channel is available, it is automatically downloaded to the users' computers via the tuners. This content can be software updates that is automatically installed. Developers can use a Marimba product called Bongo to create applications for Castanet channels. Using repeaters, a single Castanet channel may serve millions of tuners.
There are many other companies involved in variations on push concepts. AirMedia offers wireless broadcast of news and information to desktop personal computers. The BackWeb product similarly provides real-time dispatches and content.
My opinion of Push?
I don't get it. The push model seems to assume that human beings are just hungry for a fixed set of information that fits a pre-defined set of preferences. Some days I like Vivaldi. Some days I like Green Day. Some days AM. Some days FM. I'm not just a receiver of a pre-conceived, fix set of information. What I love about the Net is that I can go out and find my desires. I don't need anyone to push those in front of me.
The current applications (PointCast, Marimba) are awkward, slow, and inconvenient to use. I could discern no benefit from using them instead of using a Web browser or a Java application. I like going out on the Web and getting what I want when I want it.
My opinion is that push is most promising in its use as an automated software update service. When placed in the service of a genuine need, push is a niche solution in the total communication environment of the Internet.