Google Ads · ROAS dropped

Why did my Google Ads ROAS drop?

Google Ads ROAS drops because one of three things moved: conversion rate fell, average conversion value fell, or cost per click rose — ROAS equals conversion rate times value per conversion, divided by CPC. Adstudio compares the period with the one before it, finds which campaign carried the drop and which of the three factors moved, and checks the conversion action behind the value before it names a cause.

Ask it on your account See pricing

The numbers that matter

What to read first.

Conversion value / cost: Google's name for ROAS. Read it per campaign, because an account total hides which campaign moved.
Conversion rate: The factor most often behind a drop after a landing page, offer or tracking change.
Value per conversion: Falls when the mix shifts to cheaper products, or when a lower-value action starts counting as a conversion.
Average CPC: Rises with auction pressure or a bid strategy change, and lowers ROAS even when nothing else moves.

The method

How to break it down.

01Check that the value comes from the action you sell on: a newly added or silent conversion action changes ROAS without a single sale changing.
02Compare the window with the equal-length period before it, and find which campaigns account for the change.
03In those campaigns, split ROAS into conversion rate, value per conversion and CPC, and see which one moved.
04Read the account's change history for the same days: a bid strategy, budget or target ROAS change right before the drop is the first suspect.

How Adstudio answers it

In the app, or from the AI you already use.

In the Adstudio assistant

The assistant reads the trend for both periods, attributes the change to campaigns, and runs the campaign analysis for Search, Performance Max, Display, Video and App campaigns. It reads Google's change history for the last 30 days, so a target ROAS edit made in Google Ads shows up next to the drop. If the answer is a budget or status change, it prepares the change, has Google validate it, and applies it only after you confirm.

From ChatGPT or Claude, over MCP

From ChatGPT or Claude, query_performance returns spend, conversions and conversion value per campaign for any two date ranges, so your AI can compute ROAS for each period and see which campaign moved. It does not read the change history or individual conversion actions.

list_accounts
query_performance

Prompts

Copy one and ask.

“Why did ROAS drop in the last 14 days compared with the 14 days before? Break it down by campaign.”
“For the campaign that lost the most ROAS, tell me whether conversion rate, value per conversion or CPC moved.”
“Did anyone change bid strategies or targets in Google Ads in the last 30 days?”

Limits

What Adstudio will not tell you.

Adstudio does not have industry benchmarks, so it compares your account with its own history, not with other advertisers.
Shopping and Demand Gen campaigns are taught but not measured by the deep campaign analysis; their numbers are still read and compared.

FAQ

Questions people also ask.

Cost often moves for a while after a bid strategy or target change, so the reading of that window is less certain. Adstudio flags the change and lowers its confidence instead of calling it a lasting decline.

It reads each conversion action's activity. When the action that carries your revenue stopped recording, it says so first, because every ROAS reading after that depends on it.

Creating an account costs nothing, but connecting an ad account needs a paid plan: Hobby at $19 a month, or Business at $39 per workspace a month. There is no trial, and the price does not depend on your ad spend.