One of the first questions that comes to mind when people consider signing up with an application service provider (ASP) is, "What am I getting myself into?" How long is the commitment period if you outsource one or all of your applications to a remote host? The answer depends on the individual ASP and the kind of application you access. The more information that the ASP needs to configure an application for your organization's use, the longer the contract period is likely to be.

Dependencies on a per-ASP level make sense, but how does the type of application come into play? The type of application matters insofar as the application deployment matters. ASPs follow one of three deployment models: Web-based applications, client/server applications, and terminal server applications. Web-based applications are either custom-built with a specific purpose or Web-enabled on the desktop. They're accessible anywhere that you have Web access and a browser to support that application type. Client/server applications are database applications of some flavor. In the client/server model, a piece of the application runs on the client and operates in conjunction with the piece that runs on the server. The third type of ASP offers some form of terminal emulation, either through a display protocol such as ICA (which works with Citrix's MetaFrame atop Microsoft Terminal Server), or through a terminal-emulation package such as WRQ's Reflections (which lets end users access applications running on an AS/400). In the terminal-emulation model, the application runs on the server and only displays output on the client.

Some ASPs rent applications on a per-use basis, but more often, the commitment period is at least a month and might be even a year or longer. Enterprise client/server applications have a longer contractual period than Web-based applications because most companies don't deploy enterprise resource planning (ERP) for short-term needs and the applications require personalized configuration. It can take weeks or months to set up an enterprise application, as opposed to using a Web-based application as soon as you ask for it.

In talking with ASPs for enterprise applications, I found that a 6- to 36-month contract period is typical, but some ASPs require a 3-year commitment or will give you a better deal if you sign up for that long. Finally, for ASPs that work with several independent software vendors (ISVs), the contract length might depend on which vendor you're renting the applications from. As you can see, the commitment varies significantly, even within the models for application delivery.

Ideally, you find an ASP that you're happy to lock down a 3-year contract with. However, when you're shopping around, find out what you're committing to before you sign.