It's as good as any other signals provider.
Good for the initiators, bad for the ones who follow.

It works like this:

1. Initiators announce a pump.
2. They start the pump.
3. They tell their followers to buy.
4. Coin pumps, other market participants buy as well.
5. Initiators sell the coin.
6. They tell their followers to do so.

Result:

Initiators made tons of profit whereas most followers barely made a profit, and other market participants usually sell at loss.
Better stay away from such groups.