For example, lets say I'm currently spending $10K a month on advertising; how can I use my cohort analysis revenue data to see if my advertising spend is worth spending?
There is often the challenge of simply spending too little to get effective feedback, but at $10k that's often a number I've seen that starts to make a difference. Are you spending this all on Google Adwords?
The first number to consider is 0. No sales on $10k is highly indicative. But even a couple sales (let's say you had a $50 product) is also pretty bad from a ratio standpoint. Can you share how much revenue you've generated from $10k in spend?