Same with electricity retailers. And if your existing company sees you are churning they will call in the cool off period to (a) entice you to change with a slightly better offer, and (b) find out the competitor's price. (I always give them a lower price to match than what I've been offered, because price matching enables the incumbent vendor to rip everyone off with bad list prices and private deals).

Be careful with iselect though, I think all their resellers use the same underwriter. I.E not real competitors.