The P&L

This is where we're headed:

Let's say you want to invest an additional $100,000 in paid search. You should be able to see a p&l, presented to you immediately, showing you how the business evolves over the next five years.

Right?

Yeah, you deserve that. You shouldn't be guessing.

And yes, I realize what is depicted above is a guess ... but it is better than a random guess without the information above.

You deserve a Marketing Budget Experiment.