Sometimes it's a matter of one platform only counts raw clicks while the other counts unique + visits regardless of whether an IP has already viewed your ad or not.
Sometimes, one platform reports in real time while the other has a delay.
Maybe some of the clicks didn't go all the way through to the ad. What I mean is, if someone clicked accidentally and exited the tab/browser/whatever before they got all the way through the forwarding to land on your page. They didn't let it load.
Just a few possibilities....
Hmm,does network maintenance affect the offers?