They mount on the bottom like a spinning reel. However I use small baitcast reels on my vertical jigging poles and spinning reels on my jig and bobber or bobber and minnow poles. I don't troll but if I ever get into it I think baitcast would be the way I go on there too. Your correct though the reel is mainly just a line holder you don't use it very much with jig poles. I like baitcast because it makes it easier on me to pull line for depth and be able to keep up with it and they have a good drag for when a big catfish, buffalo, drum, bowfin, or bass decide they want to stretch your string.