Hey everyone,
When my daily budget is $20 for example, my page ctr is around 50% and cost per click around $0.06. But when i increase my budget to $200 the page ctr is around 29% and cpc around $0.20.
Now the increase in cpc kinda makes sense, because my budget has been increased but then what makes the ctr drop?
And let me mention that it was the same ad, so targeting etc and everything else was the same, the only difference was a budget increase.
Can anyone please shed some light on this matter?
Thank you.
General Hypothesis:
As you increase your budget the FB algorithm needs to find you more placements for your ad. You end up showing lower in position in a persons feed or session, less first impression traffic and lower quality performance for you.
My ROI has always decreased when I would try to increase the budget 5-10x immediately (from $20 to $100-200 immediately).
Just start increasing the budget from $20 to $30 > $40 > $50 > $75 > and so on
You surely know that FB tries to find the best audience for your ads.
But at the same time it's going to use your daily budget in its entirety, no matter what.
Two scenarios where it can affect you negatively:
1/ If during a day your ads appear more times than the number of people matching your perfect audience as determined by FB's algo, they will then be shown to others that are not as good but can still respond. Imagine a circle where the center represents your perfect audience. FB is going to try to target the center first (once it has identified it), and then will go further and further. Remember, FB will consume your budget in its entirety, no matter what.
2/ If your targeted audience is smaller than the number of times your ad is going to appear, then those people will see your ad several times per day. Check the "frequency" metric on your reports. If it's way above 1.0 then people see your ads too often.
Yeah but how do i increase my budget while still be on profits?
When my budget is $20 im in profits, if i increase it then loss. Any help?
Don't go from $20 to $200, increase it slowly as mentioned by @arlind above.
Are you increasing from 20$ to 200$?
You have to let fb to find good public for your ads on the different scenarios of budget.
I tested many times to go from 20$ to 100$, 200$ or 300$ most of the time the ROI goes down like crazy.
But If I follow 10 > 25 > 50 > 100 > 150 > 200 the ROI will be (most of the time) similar and in some cases better 
raise your budget at the start of a new day (on the accounts time). Even then sometimes it takes a day or so for your ad/campaign to settle in at it's new metrics and then performance will stabilize.