I disagree pretty strongly with your comment re: pricing model. For services like this, the incentive to upgrade is going to be there regardless of price, since there's a strong incentive to have your entire company / department using the same tools.
Atlassian is a great example of an extreme version of this. The cost for me to have 10 users (on-premise, but hosted is similar) is $10 ($1 per user). The cost to have 11 is $800 ($75 per user).
It's a smart, if unintuitive pricing model - you can demonstrate the value of your product to cash-strapped startups that are going to be extremely cost-conscious, and start charging more on value once the company has started to see success.
Atlassian is a great example of an extreme version of this. The cost for me to have 10 users (on-premise, but hosted is similar) is $10 ($1 per user). The cost to have 11 is $800 ($75 per user).
It's a smart, if unintuitive pricing model - you can demonstrate the value of your product to cash-strapped startups that are going to be extremely cost-conscious, and start charging more on value once the company has started to see success.