Database Access? On site or off?

[wxdqz]

Hey guys/gals I've got a small client who wants to integrate his website with his inventory control system. I can do the integration, but the question is if the main inventory database should be onsite (with the website accessing data through a cable connection) or offsite (with the store accessing data on a server elsewhere over the cable connection).

I was hoping someone else has run into the question and had some insights.

Thanks,
Devin Pittman