Hey
I've figured this out on every campaign I'm doing and every traffic source (FB, TJ, POF, ...). What I've discovered so far is that week days vs weekend days could be completely different.
Maybe a campaign works very well during the week and totally sucks in the weekend or the opposite happens.
I see here two solutions:
a) Leave it running, even if you're losing just to get more data. (This usually happens when I started creating a campaign like 2 - 4 days before weekend; otherwise it usually works well)
b) Pause it until the campaign is tested very well during the week, has a positive ROI and then continue testing on the weekends.
I'm currently testing new campaigns anyway so it's totally okay to buy for data but I wanted to know how you guys handle this situation. And it's obvious that this changes again on every campaign/angle/whatsoever.
Thanks a lot
SwissFactor
I'm assuming you just run dating?
Why not run a week day campaign and a separate weekend campaign with lower bids?
Yes I'm running dating only. Never thought about this one. Good idea. Thanks a lot.
Maybe it's a beginner thinking but I usually hate cutting stuff or using day parting. I always think "if i cannot make it work the other way around then I'm just not yet there!" or "Or I failed because I cannot make it work without using these tools." (tools => day parting for example).
Thanks again for your answer
PS: Sometimes I test 20 different landing pages of a campaign which has - 90% ROI because in my imagination I see THE experienced marketer who is able to make every campaign profitable and if I ever want to come close to a good & experienced marketer then I need to test, test & test more... 
Edit: But I think more and more of it as a total wrong & fucked up mindset and I should use whatever tools & settings are available in my favor. But I'm not sure... :-/
Haha sorry I don't quite understand your last post? Is that a question?
No I realized that I was standing in my own way by not using all the tools available like day parting and by trying hard to optimize campaigns that dont have potential after some initial tweaking.
=> You helped me I'm fine, thanks Mr. Green ;-)