At least it enables you to crystallize your loss.
For some the $150 wont be worth it... if your sitting on a large loss with gains to offset then it would be worthwhile.
Again, I have never used the service so cant comment on the worth of this, anyone considering it should speak with their accountant first I would imagine.
The risk they take is that they end up with tonnes of shares worth nothing but as @Zestfulmocha said they only need a couple to come off to make their money.... it is a business after all.