Seems a bit steep, but as an ICO I imagine they have gotten lots of funding and this is an easy and fast way to promote their product. I would guess after they hit so many signups they will decrease the reward.

Ahah just saw it in one of their posts "There is a cap for this as it counts as part of "pre-ICO promotional activity" - more details about this will be released in the coming days along with ICO fund distribution."