If you sell to businesses, this is a horrible idea. I'd rather you charge me $150/month and have no one use the service than have to explain to my boss, "Why ar

If you sell to businesses, this is a horrible idea. I'd rather you charge me $150/month and have no one use the service than have to explain to my boss, "Why are we paying $110 this month, when it was $70 last month and two guys no longer work for us?" Also, customers are paying for the option to use your software at any time without signing up again. You're providing some amount of value just in holding their data on your system. You shouldn't avoid capturing that value.