I've currently been working on a few campaigns that has been making me decent ROI, and the best part of it is that i can still scale it much bigger but the only thing that's holding me back is my credit limit.
I'm already (almost) maxing out 4 cards. I stopped all of my other new offers/camps that I've been testing trying to get it to work just to allocate budget for this.
I hear about milking an offer as much as possible, but I don't like the feeling of relying only on 1. But at the same time allocating like $50-$100 a day on another offer/camp seems too insignificant for anything. And even IF it works out, how are the budgets gonna be split?
Would love to hear your thoughts, thanks guys
I personally think you should focus on the winning campaign, i am pretty much on the same boat, found 1 profitable campaigns and trying to scale that one only.
Let say you really find a few more profitable campaigns, you won't have any cash to scale it anyway.
But i am no expert so lets wait for more pros to chime in 
I made this mistake, I was too busy scaling that I didn't think long term.
e.g. what offers/vertical/geo will replace the current winning one when this one dies.
I'd hire someone that can launch campaigns while you think on the long term strategy of your business.
but if you're still early stage, just focus on scaling and get as much $$$ as possible so that you can hire someone later.
Id say milk your campaign for every last drop. This is an industry of ups and downs. In scaling, youll find new traffic sources or angles that can help your next campaigns.
There is an A and a B to this problem.
Johnaff named the A - every campaign will die at some point, so from the UP you will get to the DOWN sooner or later. Once the campaign is down, you will regret you didn't milk it some more, its always the case.
But there is also the B, as thuglife pointed out, if you focus 100% at the winning campaign and abandon everything else, you will find yourself with nothing to run once the campaign dies - and trust me, every campaign dies once.
You need to mix these two if you want to stay in this biz for the long-term - focus on the money makers, but still keep looking for new opportunities and test new stuff. Your problem right now is the limited budget, in this case you don't have much options but to go full throttle with the winning campaign and build up your capital as much as you can so you don't have to face this problem again - so pretty much agree with what thuglife said 
If this campaign is a winner, I would milk it hardcore mate. And if it dies, why not re-launch it with other angles.
1) You know how it converts
2) You know the network/advertiser (who probably paid you already or you have good conditions with them). Also you might get a higher payout since you have proven yourself and you have shown to be reliable and steady, right?
3) You have learned what works now (although it's often hard to point out which parts really make it a winner) and you have learned what doesn't work.
Combine those two so you might even reach a better ROI on the same campaign with other angles?
I have milked some pin submit campaigns over 3 times (with some weeks in between to give it a rest) with 100%ROI at least, on same audience!
@Gijs,
You guys gonna be poppin' bottles tomorrow in milan?
Hope to see you all at the meetup tomorrow to continue these interesting discussions accompanied with a few drinks!
Focus on making as much as possible in the moment until you have made significant money ( 100k + ) and gained experience. Long term thoughts and planning will be much more valuable and realistic once you have that knowledge. If starting capital is also a concern, this becomes even more true. Good luck!
Great - hope see you at one of the next events Gijs!!
Haha. About the scrubbin. Sad but true - many (cowboy) networks still do this!
I'm 1000000% with John on this one.
Milk the fucker!