Yes, and those caps and alerts should be seen as beneficial to the service provider as well as to the customer. I wouldn't want my customers to have surprise high costs. A well-designed cap or alert should help avoid any major surprises, and should avoid the awkward situation of customers having to ask providers to forgive large bills that were accrued accidentally.
Bitter customers are not good in the long run, and caps and alerts help avoid having bitter customers.
Agreed, alerting and hard-capping (limiting consumption) should be seen as different kinds of thresholds, possibly defined independently by different parties.
I'm looking into implementing this system in one of my projects, do you have good resources on this matter ?
I do not, but as a consumer I appreciate the option to choose between an alert and a cap, or some combination of the two. There are some projects where I'd want the cap to know I might get an interruption but will never get a large bill. There are others where I need to keep the service up, and an alert would be much better than an interruption.
Bitter customers are not good in the long run, and caps and alerts help avoid having bitter customers.