CPRU = Budget Spent x ( Conversions x N-day Retention Rate )

Well, I guess CPRU is not that hard either.

So, if you have a budget of $10k, 1000 conversions and a Day 1 retention rate of 20%, you actually have only 200 converted users at an acquisition cost of 50$/user. If you manage to raise your Day-1 retention rate to 25%, you’ll have 250 users at a CPRU of 40$. By increasing Day 1 retention rate you get more valuable users at a lower CPRU.

This way, you’ll know exactly how much you pay “per user” as opposed to a bleak conversion.

Why CPRU is the new metric in Performance Marketing