Ask HN: What questions should a business ask an ASP before signing up?

There have been quite a few discussions around here about experiences with different hosting and SaaS providers, but I have a more general question: what sorts of diligence questions should a business ask an ASP or email hosting service before signing them up? I'm more curious about ASP and email hosting than managed hosting companies. So rather than questions relating to how their infrastructure and business will keep my server or slice running (managed hosting), I'm thinking about situations where the provider has a shiny package of software/services that they have built their systems to run. I'm curious what sorts of questions people would ask to get more comfort that they've got their bases covered.

I've found myself wondering about security, data integrity, backups, DR, etc. for a number of these firms, and I can't help but wonder if there are questions I should be asking that I've missed. At the end of the day, it requires a leap of faith- but I'm guessing there are plenty of small businesses out there using these services who might not have the breadth of expertise to ask all the right questions before taking the leap.