My DD6 goes to Rainbows. When she was almost 5, I put her name on the waiting list as you have to be 5 to join. They said she was unlikely to get a space as they have an 18 month waiting list. There are 46 girls on the waiting list.
I asked if I could volunteer so she could skip the queue, and she started the week after she turned 5.
In our unit of 15, 3 go to private school, 10 go to two different outstanding school around a 0.5 miles away and 2 go to the good school next to the scouts hut. I would say 75% of the children will be MC and all live in two parent households. We live in a affluent area, with a choice of excellent schools. None of the 15 children are on FSM and none of them have EAL. All can read and write to their appropriate levels.
If you travel 3 miles down the road in the same town, the Rainbows is not oversubscribed at all. The children in that catchment area have a choice of 3 good schools, two of which have a BU, and all of them are in lower income areas. They have a higher than average FSM, EAL and many of them get support with fees. Almost all of them will be WC.
Area completely dictates how MC or WC a unit will be.
Our units termly fees are £50 instead of £30 for the latter unit. With the additional fees, we hold an outing once a term (rock climbing, zumba classes, cinema, pantomimes etc), and have an outside agency come to see us once a term, such as an animal holder, or Elsa for their Christmas party).