I do not have any idea on how ICO promotion goes with signature campaigns but promoting some type of bitcoin related services and products can be very effective. For instance, if you own a gambling related website that allows players to play with BTC and win in bitcoins. There cannot be a better place than this to advertise such a platform here. The members here are already those who transact with crypto and thus may be interested. We should also not forget that the posts made here may be getting good amount of traffic from Google so those visitors may try that product or service in signature.