>I can't argue your points 'cus they're valid, but most mom-pop-shop can't go to SQL server or Oracle.
>So that leaves only something like MySql or ...Access(?)
>

SQL 2005 Express is free. Oracle Express is free. They can afford those if you support them in your programs. Some of your small shops may already be using SQL 2005 Express (among others Microsoft Retail Management System and Small business Accounting both use it)..

I've worked with MySQL before - it's OK but decidedly primitive compared to SQL Server. It is free for larger systems though (unless you want dedicated support).

Access is still a file based database. It doesn't use an 'engine'. I stay away from that personally.