Updated 2026-11-06

How to spot wasted Google Ads spend in Looker Studio (scatter + impression share)

One campaign can look fine on ROAS until you put cost next to conversions and open impression share. Healthy CPA on Search can still hide keywords with high cost and zero conversions, or a brand campaign that loses half its eligible impressions to budget while Display burns spend. Looker Studio (now Data Studio — Google changed the name back in 2026) makes those leaks visible on one page when the right fields are wired.

This guide shows how to spot wasted Google Ads spend with a cost-vs-conversions scatter and impression share columns, using Google’s free native connector. Follow along on our free Google Ads Looker Studio template (it already has a Wasted Spend page), or rebuild the same structure yourself.

What “wasted” means in this report

“Wasted spend” is not a Google Ads column. It is a working label for money that is unlikely to pay for itself under your current goals. In practice we look for three patterns:

1. High cost, low or zero conversions — a campaign, keyword or search term that keeps spending while the conversion column stays flat.
2. High CPA / low ROAS outliers — rows that convert, but at a cost that breaks your target.
3. Lost opportunity on winners — campaigns that convert well but lose Search impression share to budget (you are underfunding what works) or to rank (bids, ads or landing pages are holding them back).

The metrics we use come straight from the native Google Ads connector so your report matches the Ads UI when date ranges and conversion settings align:

If you track value, keep ROAS next to CPA; otherwise lean on Cost / conv. and raw conversions. Label the column clearly — “Conversions” (primary) and “All conv.” are not the same, and mixing them is why clients often say the report is “wrong.”

Native Google Ads connector: fields you need

You do not need a paid connector for this. Google’s Google Ads connector is free and exposes Overall Account Fields, including impression share.

1. In Looker Studio / Data Studio, Create → Data source → Google Ads.
2. Authorize access, pick the account (or an MCC and then sub-accounts), choose Overall Account Fields, and connect.
3. Confirm Cost, Conversions, Search Impr. share, Search lost IS (budget) and Search lost IS (rank) appear in the field list.
4. Prefer Owner’s credentials for client-facing reports (viewers see data through your access) and Viewer’s credentials for internal templates where everyone already has Ads access. Google documents the difference in About data sources.

Add a date range control (default last 28 days, compared with the previous period) and a data control so anyone with account access can swap in their own Ads account without editing the report. That single control is what turns a static dashboard into a reusable template.

Scatter setup: cost vs conversions

The scatter is the fastest way to see waste without reading every row.

Suggested chart settings

• Chart type: Scatter
• Dimension: Campaign (or Keyword / Search term on deeper pages)
• X-axis: Cost
• Y-axis: Conversions (or Cost / conv. if you prefer efficiency on the vertical axis — keep one convention per report)
• Bubble size: Clicks (optional; large bubbles that sit low on the Y-axis are loud)
• Colour: Advertising Channel Type or Network, so Search, Performance Max, Display and Video separate visually
• Filter: Campaign status = Enabled (or include paused only when you are auditing history)

How to read it

• Far right, near the bottom — high cost, few or zero conversions: pause, tighten targeting, or mine search terms for negatives.
• Far right, high up — expensive but converting: check impression share before cutting; they may need more budget.
• Left, high up — efficient winners: protect them.
• Middle cluster — noise; use the table’s CPA/ROAS thresholds instead of chasing every dot.

Put a table beside the scatter with Campaign, Cost, Conversions, Cost / conv., Conv. value / cost, Search Impr. share and both lost-IS columns. Heatmap Cost / conv. and lost IS. The free template’s Wasted Spend page uses this layout; the setup guide shows the same scatter at keyword and search-term grain.

Caveats worth labelling on the page

• Keyword and search-term scatters only exist for campaigns that use keywords. Performance Max will show on campaign-level charts but not on classic keyword tables — say so in a note so nobody thinks data is missing.
• Recent conversions still trickle in. The last few days can move after you first open the report.
• Match the Ads UI time zone and the same conversion actions, or the scatter will disagree with what the client sees inside Google Ads.

Impression share: budget leak vs rank leak

Impression share answers a different question from the scatter: not “what spent without converting?” but “where are we leaving demand on the table?”

Google publishes the definitions in Get impression share data. For Search campaigns, focus on:

• Search Impr. share — the share of eligible impressions you actually received.
• Search lost IS (budget) — the share you lost because the campaign hit its budget.
• Search lost IS (rank) — the share you lost because Ad Rank was too low (bid, expected CTR, ad relevance, landing page experience, and related factors).

Reading the two lost-IS columns

Brand campaigns deserve a special look. Lost IS (budget) on brand usually means you are paying for someone else’s click on your own name — an expensive habit. Non-brand winners with high lost IS (budget) are the opposite: underfunded demand you already know how to convert.

Display and Video often expose different impression-share fields. Keep a channel filter on so you do not compare Search IS where it does not apply the same way.

A 15-minute weekly agency workflow

1. Open the client copy (or copy the master) and confirm the data control points at the right account.
2. Set last 7 or 28 days with previous-period comparison.
3. On the scatter page, list every campaign in the high-cost, low-conversion corner.
4. On converting campaigns, note one budget move (lost IS budget) and one rank/quality move (lost IS rank).
5. Pull negative-keyword ideas from search terms on the worst spenders.
6. Write three client bullets: what changed, what you did, what’s next. Schedule PDF delivery if that is in the retainer.

One master plus one copy per client is enough for freelancers. MCC roll-ups help when you manage many accounts — that is the soft upgrade below, not a requirement to start.

Get the free template (and notes by email)

The Google Ads Starter template already includes Overview, Campaigns, Wasted Spend, Keywords & search terms, and Audience/device pages built on the native connector. Open it, use the data control to preview your own account, then Make a copy and swap the sample source for yours.

If you want pack notes when we ship related templates (GA4, Search Console, multi-client updates), leave your email on the homepage email signup or the form on the Ads template page. No paid connector required for the free starters.

When Pro is worth it (soft upgrade)

Stay on the free single-account templates if you report on one or two accounts. Consider the multi-client & white-label pack ($39 one-time, 14-day refund) when:

• You need a roll-up across many Google Ads accounts or GA4 properties without rebuilding blends by hand every month.
• You want a white-label client page with your logo and colours instead of editing branding per copy.
• Setup time matters more than tinkering — the pack includes a short setup guide and email support.

No countdown timer and no fake scarcity. If the free Ads template already covers your workflow, use it.

FAQ

Is it Looker Studio or Data Studio?

Both names refer to the same product. Google rebranded Data Studio to Looker Studio, then in 2026 started using Data Studio again in places. Field names and the Google Ads connector work the same either way. We use “Looker Studio (Data Studio)” so searchers on either name land on the right instructions.

Do the screenshots use real client data?

No. Site screenshots and the public demo use Google sample / demo-account data, not a live client account. After you copy the template and connect your own data source, you will see your numbers. Treat every screenshot as illustrative.

Do I need Supermetrics or another paid connector?

Not for standard Google Ads reporting in Looker Studio. The native connector covers cost, conversions, impression share, keywords and search terms for this workflow. Paid connectors help when you mix Meta, LinkedIn, TikTok or other non-Google sources into the same report.

What if my numbers do not match the Google Ads UI?

Check date range and time zone, Conversions vs All conv., chart filters, and data freshness. Conversions can also land days after the click. Full checklist: Google Ads Looker Studio template guide.

What is the refund on Pro?

$39 one-time, 14-day full refund if it does not fit. See Pro and the refund policy.

Next steps

1. Open the free Google Ads template and preview with the data control.
2. Confirm the Cost × Conversions scatter and both Search lost IS columns.
3. Run the 15-minute weekly checklist once on a live account.
4. If you outgrow one-account copies, see the multi-client pack — or stay free and get updates by email.

Waste shows up when cost, conversions and impression share sit on one page. You need the right fields and a habit of reading lost IS before you raise another budget — not a $1k connector.