Read their diary

There's nothing wrong with doing a little snooping to find out what type of people you are committing your property to. Query the Whois database and find the business address of the server. Use a tracing program to view the path to the machine in the Whois database. If another ISP's server pops up, chances are you're dealing with a reseller rather than an actual host. Check out the other sites on their server. If most of them are spam sites, banner click-through pages or porn sites, being associated with them could have a negative impact on your business.