Of course, I think most of us would likely prefer sports betting over free spins. Because to be honest most of us here are more familiar with sports betting, including myself. though just like as you mentioned I think free spins are spent faster than free bets because I could remember the last time I used my free spins it was some how complicated for me, although am not use to it before. my favorite is sports betting because that is the one am more familiar with, so I was very excited about this free bets, all thanks to Whale.io for this incredible development.
Good to hear that we have some more sports fans on this forum and surely now they can also get free bets thanks to Icopress and Whale.io. Well, sports betting is always preferred for the ones who are good at research and they know that how a bet can be a winning one and how one can be a losing one. It's not hard to get good at sports betting and with free bets it's more enjoyable.
I also clearly prefer sports betting to classic games such as slots and so on. This is simply because I have a bit more control with sports betting and it's actually my fault if a bet goes wrong. Also, as you rightly write, with a little preparation (game studies, etc.) you can definitely get more out of your money. However, this only works if you are familiar with the respective sport and league. Wildly betting on any games (or purely according to odds) is otherwise more akin to gambling.
That's why I think it's a great campaign by icopress and whale.io to hand out free bets on sports games!