About 15 years ago we launched the concept of virtual users. We were the first and we did it for free.

The reason we didn't charge for it because we thought they will be mostly used for a few users that the manager wanted to track but who were not going to log in. We even allowed them to update tasks and even log time via email. 

Now virtual users also take up resources - CPU and disk. Scheduling is quite CPU intensive. Scheduling not just happens when you schedule tasks but also when you see the workload charts. Everything is calculated in real-time. 

Virtual users also use non-trivial product functionality; we think it needs to be paid for.

If the number of virtual users is small relative to the actual number of users, we can take it in our stride. But we have observed amounts to abuse. We observed customers with 5 users and 100+ virtual users or with 10 users and 500+ virtual users. This is something we did not anticipate. They are taking away too many resources without paying for it. 

The reason we are able to offer an enterprise-class product at $25 per user is that we are efficient. This price level is unheard of for our capabilities and we'd like to keep it this way.

Hence, we are restricting the number of virtual users you can have based on the following formula:

Virtual Users = 10 + 5 × Licensed Users

For example, if you have paid for 12 users, you will be able to create a maximum of 10 + 5 × 12 = 70 virtual users. We think this is a generous limit. It will prevent abuse and put the resources back in the hands of customers who have paid their fair share.