Glossary

Cost / Spend

Cost (or spend) is the total amount an ad platform charged for a campaign, ad group, or account in the selected period. It's the denominator of every efficiency metric (CPC, CPA, ROAS) and the number that has to match the client's media budget.

How to read it

Watch pacing, not just totals: spend distributed unevenly across a month distorts weekly comparisons. Budget caps and alerts catch runaway spend before the client's invoice does.

Where it misleads

Google can overspend the daily budget on strong days (up to 2x) and balances it over the month. A single expensive day is not a bug, a consistently blown month is.

Related terms

CPC (Cost per Click) →

CPC (cost per click) is the average amount you pay for one click on your ad. It reflects competition for your audience: the more advertisers bid on the same keywords or users, the higher the CPC. It's the price tag on your traffic.

CPA (Cost per Acquisition) →

CPA (cost per acquisition, also cost per conversion) is the average amount you spend to get one conversion. It's the efficiency metric for lead and signup campaigns: as long as a customer is worth more than their CPA, the campaign makes economic sense.

ROAS (Return on Ad Spend) →

ROAS (return on ad spend) is the revenue generated per unit of ad spend: a ROAS of 4 means €4 of tracked revenue per €1 spent. It's the core efficiency metric for e-commerce campaigns, connecting spend directly to the money it brought back.

Metrics explained are nice. Metrics watched are better.

HeyMetrix monitors all of these across Google and Meta, with alerts and a nightly AI briefing.

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