The marketing mix section answers one question: where should the next dollar go. It does that using blended efficiency across every channel rather than each platform’s own account of itself. This guide is for whoever allocates budget. It explains why platform ROAS is misleading in isolation, what blended efficiency measures instead, and how to use both without fooling yourself.
Why platform ROAS lies on its own
Every advertising platform is graded on its own homework. Meta decides which conversions Meta caused. Google does the same. Klaviyo does the same for email.
None of them is lying, but they are all answering a generous version of the question. If a customer sees a Meta ad, searches your brand name on Google, then clicks an email before buying, all three platforms can legitimately claim that order. Add up the platform reported revenue and you will frequently find it exceeds what your store actually took.
That is the arithmetic problem. The decision problem is worse. If you increase spend on the channel with the highest reported ROAS, you often increase spend on the channel that is best at claiming credit rather than the one that is best at creating demand. Brand search is the classic example. It reports spectacularly and mostly harvests intent that already existed.
What blended efficiency measures
Blended efficiency divides total revenue by total advertising spend, across everything, for the same period.
It is a cruder number and a more honest one. It cannot be inflated by attribution, because it never asks which channel deserves credit. It only asks what you spent in total and what the business earned in total.
Read it as the control. When blended efficiency improves while a platform’s reported ROAS falls, the platform is losing visibility rather than losing effectiveness. When a platform reports a triumph and blended efficiency is flat, the platform has taken credit for revenue that would have arrived anyway.
Use them together
Neither figure is sufficient alone. Blended efficiency tells you whether the whole machine is working. Platform figures tell you which lever moved.
The practical method is to make one meaningful change at a time and watch blended efficiency over the following weeks. If you raise prospecting spend on Meta by a third and blended efficiency holds, that spend is creating incremental demand. If blended efficiency falls by roughly the amount you added, you bought revenue you already had.
This is slower than reading a dashboard number and deciding immediately. It is also the only method that survives contact with attribution windows changing, which they do without warning.
Where Tatheon differs
The marketing mix section shows platform claims and reconciled contribution side by side rather than choosing between them. The gap between the two is itself the signal. A stable gap is normal and tells you how much each platform habitually overstates. A gap that suddenly widens usually means tracking broke or an attribution window changed, and both are worth investigating before you act on the underlying numbers.
What to do with it
Look at blended efficiency first, over a period long enough to be meaningful, which for most brands means weeks rather than days. Then look at which channel changed. Then check whether the reconciled contribution agrees with the platform’s story before moving budget.
If the two disagree, trust the reconciled figure for allocation decisions and use the platform figure for optimisation decisions inside that platform. The platform knows which of its own ads worked. It does not know what your business would have earned without it.