So you’re selling a classic, on-premise application, and your marketing team insist you need a SaaS version, and fast. How do you do it ? By buying up some big servers in a hosting facility and running a separate instance of your software for each customer. Seriously. A separate copy of the software for each client, with the obvious problems of scalability and manageability (like when you’ve got 300 customers and need to roll out a bug fix) and limitations in potential for sharing and communicating. This is called Single Tenancy and it's frustrating because when these suppliers and their customers hit these problems, SaaS will undeservedly take a kicking. But I've seen a number of vendors doing it recently, from very small to very large. If you're considering using SaaS for any application, make sure you understand this Single- versus Multi-tenancy aspect because it gives you a good clue how SaaS-ready the vendor is. Phil Wainwright's recent article is a good place to start. Or talk to us.