i have never used their predictions and will not, because the predictions provided by the betting prediction site are someone's analysis, and because they are the result of someone else's analysis i do not trust them as my decision on the bet. i am more confident in the results of my own analysis and bet on it. it doesn't matter that it will lose in the end, at least it is the result of my analysis and i don't trust other people to decide on my own bets.
Even if you don't want to make use of those prediction sites, sometimes, as a gambler, it's good to compare your own prediction skills with those of others.
Also, those who are still new to sport prediction are the ones who often make use of it, as they can use that way to learn how to make predictions, and from there they can perfect their own skill in the way it will suit them better.
To me, those prediction sites are never meant to be seen as having 100% accuracy, as it's humans like us who also make predictions.