Short version: Budget allocation is the decision of how to distribute money across campaigns, channels, audiences, offers, or tactics.
In marketing, it decides where spend goes and why. A team might allocate budget between Google Ads, Meta Ads, SEO content, email, production, testing, and retargeting. In ad platforms, budget settings also control how much a campaign is expected to spend over time, while delivery systems may pace spend differently depending on traffic and predicted opportunity.
Good budget allocation is not an equal split by habit. It should reflect the campaign objective, audience stage, expected return, creative readiness, measurement quality, and risk. Some budget should support proven performers, and some may be reserved for testing new angles. The key is to reallocate based on evidence rather than emotion.
Related terms: ROAS, CAC, and attribution.