Why there is a 20% limit?
Keep an eye on your CPM
- Sustain losses: If your budget is $20 and your CPM is $10, you get 2,000 impressions. CPM means how much you pay for 1,000 impressions. If you increase your budget three-fold and set $60, for instance, you don't get 6,000 impressions because your CPM will increase and become $20 (not $10). It means you get 3,000 impressions (not 6,000).
- Optimization starts again from the very beginning and it negatively affects your ad performance.
After increasing the budget by 20%, pay attention to your CPM, it shouldn't increase by more than 20%. If it increases too much, you may get the same number of impressions which means you may pay more for the same number of impressions and it's a waste of money.
If we get back to our previous example when your budget is $20 and your CPM is $10, you get 2,000 impressions. In this situation, your CPM should be no more than $12.
For instance, each time you increase your budget by 20% and your CPM changes this way:
- $15 budget and $10 CPM
- $18 budget and <$12 CPM - This is Ok as $10+20%=$12
- $21.60 budget and $13 CPM - This is Ok as $12+20%=$14.40
- $25.92 budget and $16 CPM - This is NOT Ok as $13+20%=$15.60 and if there is $16, CPM increased by 24% (not 20%). At this level, it's time to stop increasing budget as you pay for a less number of impressions which means you lose money.
Wait and see how your CPM changes and don't increase amount till reducing CPM. If your CPM didn't reduce in about 4 days, reduce your budget from $25.92 till $23 for instance. Summary
. This scaling method has 3 rules:
- Scale (increase budget) not earlier than in 24 hours
- Increase budget by no more than 20%. You may increase by less than 20% but not more.
- Your CPM should be increased by less than 20%, otherwise, it makes no economic sense.