Class Dojo - what's that all about then?!

[simpless]

My dd's school has recently introduced Class Dojo. I know this from talking to my dd - the school hasn't informed parents in any way.

Today, I got a faux sad email from my dd's class teacher (who hates her/me - I've had to make a serious complaint about this teacher recently after they acted v unprofessionally), telling me that my dd's percentage of positive praise last week was too low. I think (??) that may have been her telling my dd needed to behave better (?), but it could be read as the teacher needs to be more positive and less critical all the time. There was no explanation.

It seems a ridiculous system - surely a child can't be 'measured' (given percentages) in any meaningful sense by a system that is entirely down to the subjective choice of a teacher to give meaningless points? I know the week they first introduced the system, my dd got negative points - the following week, I complained about the unrelated matter and entirely coincidentally my dd came top in her class with the highest number of Dojo points.

What is the point of Class Dojo? Is it really as ludicrous as it appears? Or can those who work with it or whose dcs' schools use it tell me how its supposed to work?

We did do it...then gave it up because it was just a massive faff to be honest.
The novelty very quickly wore off.

We have it, but it only seems to be used to give positive points - or at least DD has never had a negative in over 2 years and while she is well-behaved she is certainly no angel.

We have a parent log-in and get updates on Fridays. Kids were quite keen for about 3 weeks, but DD hasn't even asked what her score was for the last 6 months now.

I use it in my classroom, but just the positive points, not negative ones.

It is competitive, but I only do it for a day, or sometimes even just a session, depending on how I'm reading the class that day. So the points don't accumulate, they get wiped at the end of the day/session, so there's no child that consistently ends up falling behind. I'll admit that I often tweak who is getting points to make sure children are getting a chance of winning, and I find it useful for some of my more challenging students as they are motivated by it, and it gives them something visual to see.