Aside from that, I don't think I've ever given my c/c number for any "trial period" offer. I've mostly ever used the usage of that scheme as a red flag to steer away from the business before even considering signing up for anything.
This is not merely because I'm lazy and I don't want to even think about remembering to cancel but because I probably wouldn't want to use such a service at all. The shabbiest businesses are heavily infested with this sort of trickery, but even some good businesses have followed. It doesn't bring any value to the user except one more place where you c/c details can leak away, one more thing to remember and potentially an extra charge that will just upset you.
Trial periods can be implemented without a credit card if you really want to.