To compare channel performance for budget allocation, you need more than a ranked list of ROAS by platform. You need a process that accounts for new versus returning customer revenue, marginal efficiency as spend scales, channel interaction effects, and your actual break-even threshold, then converts all of that into a specific reallocation decision. Most founders compare channels using a single metric and a gut call. That approach works until a channel that looks weak on its own number turns out to be doing critical upper-funnel work, or a channel that looks strong is actually just capturing demand other channels created. This post walks through an eight-step process that produces a defensible, repeatable budget allocation decision instead of a guess dressed up as analysis.