How do I know whether to diversify or focus my sales and marketing efforts?

Proof gives you the ability to compute attribution against a particular outcome that you are looking for, and generate a stack rank of your investments. This is key. Because almost everything you spend money on in marketing is expensive.

Invariably, our customers find that the top 3-4 were providing the majority of the lift and the bottom 5 or 6 were all fractions of 1%, but they were equally expensive as the ones at the top. Once you know where your efforts are paying off, you can diversify across a smaller range of investments – and focus on them.