From my web host's FAQs, CPanel's documentation, and other MySQL sources of information, my understanding is that all MySQL databases for all the virtual accounts on my web host's server are stored in the same folder /var/lib/mysql.
Further, each database is created and maintained with a different and unique name initially specified by the account owner and modified by Cpanel to include the account name as part of the database name.
Although a long-time reseller (in web years anyway), I've little experience with php/MySQL other than BB applications and simple scripting.
However, my most current project will require that my "sold" accounts have a php/MySQL environment, with a dedicated IP address, uploading and indexing files to the database.
Once I reach the level of sales to support the dedicated server monthly fee, am I best served to use a DS or continue selling virtual accounts, or does it matter?
BTW, I do understand the additional support aspects of maintaining my own DS, just haven't had the need to until now.