If you run a SaaS business (or want to), then you might want to bookmark this in-depth post from Jason Cohen, founder of WPEngine. I could say it discusses the cancellation rate in SaaS business models, but I don’t think it does the post full justice. He discusses everything from the different kinds of cancellations to dealing with why a customer would cancel in the first place.
Also interesting note: WPEngine logs every cancellation — “spending time running after folks to wring out the cause.” It’s a good example for business owners today — as that information would be vital to any operation.