1. Your IT team needs to plan for your project
. Let's face it: any software or Web project is going to touch IT somehow. Even something as simple as moving your website requires IT to do something. By bringing in IT early, you can allow them to plan to dedicate some of their resources to your project.
2. IT may not want the maintenance but will be called in anyway
. Matt's 7-hour car trip aside (7 hours in a car, 7 years as head of two IT departments -- same thing, right?), anyone in IT can tell you that, despite trying to get out of it, they'll have to help you out with maintenance of anything that touches computers. Very little is as frustrating as being surprised with product questions for a product you didn't know existed. Oh, and don't forget that the marketing department just might complain to executives that IT doesn't know what it's doing when IT can't answer that surprise question...
3. Marketing does not understand IT
. If you want IT's time and attention (you know you will need it at some point during the project), try to understand their priorities. Businesses cannot survive without their technology, so IT's primary purpose is to keep the virtual lights on. That puts your request at the end of a very long list. If you get IT involved in your decision-making process early on, you have a better guarantee of IT's resources when you need them.
I agree with Matt that having
a full strategy
in place is the key to any large Web project. I even agree with Matt that IT should not make the final decision. However, failing to bring IT into the process after you've narrowed down your software choices to 3-5 different products or platforms practically guarantees failure. At the very minimum, it guarantees a lack of IT resources dedicated to you and continues to sour the already contentious IT/Marketing relationship.