It's also very bad at concurrent users if you do go down the path of dropping it on a network share if it's a normalized schema, since there's no server to cache queries or do optimizations... for strictly data entry against a simple schema you can maybe push it to low 100s of users, but backing up / restoring / rolling out new versions is a nightmare when the frontend and backend are commingled like that. You can deploy different versions of .mdbs if you have an external backend, though I've never seen anyone do so with an Access database backing an Access "UI" project...