[rogerbinns]

> Even with one account, you can put all your work-related boards in an organization and keep them separate from your personal boards that way.

But that means the credentials, access logs etc of one account are being used for both work and personal data. If for example the account you use is a work one (using Trello's google account login) then should you leave/be terminated by the company then they will disable/delete that account and now you've lost access to your personal stuff too. The other way around where work grants your personal account access to the organisation boards severely increases the risk as you'll have your personal account tied to more devices and people than a work account. For example it wouldn't be unreasonable to let your spouse know your personal account details, or to have your account also set up on one of their devices, or on shared family computers.

> I assume Dropbox doesn't allow multiple accounts ...

You can actually use multiple accounts - they just don't make it convenient. You can definitely run multiple instances of the dropbox client providing they are setup to have different home directories. This is somewhat trivial on Linux and more difficult on the other platforms. When accessing the dropbox site they have a half hearted attempt at multiple account support, but it is better to login/out and use one account at a time.

What they should do is let you enter multiple accounts in the client software. It is fine if that is only allowed with paid accounts.

[rogerbinns]

I should also add that if you are using personal accounts for work boards then the work administrators have to keep a mapping somewhere (eg [e-mail] is [e-mail]) and that the employee leaving means having to go through and find all the personal accounts and remove them from any company boards. This is a logistical nightmare!