Should I have 1 or many repositories?

Question

I've found myself asking the question: should I make one repository for all the projects at this client? or should I make a separate repository for each?

Which do you normally decide?

Please list the advantages and disadvantages of either approach which lead to your decision.

EDIT: Please mark as duplicate for one of the following:

One SVN repository or many?

Should I store all projects in one repository or multiple?

Answer 1

I have one large repository for the same reasons as Ken's answer:

One SVN repository or many?