At a glance
A cross-channel table that lists Pinterest ad landing pages with poor Core Web Vitals AND a conversion rate well below your account average. The two conditions together are the signal: a slow page on its own is a maintenance task, but a slow page that is also under-converting paid Pinterest traffic is actively losing money. Pinterest’s long save-to-purchase lag makes this worse than on other channels. A Pinner saves a Pin today and returns to the landing page weeks later; if the page has regressed in speed since the save, the deferred buyer hits a slow page and bounces, breaking a click-through you already paid to earn weeks ago.
| What it lists | Landing pages receiving Pinterest paid traffic where loading performance (Core Web Vitals, principally Largest Contentful Paint) is poor AND conversion rate is materially below the account average. Each row is one page with its vitals and its conversion gap. |
| Why it is cross-channel | The performance data comes from your website performance connector (field data and lab data); the traffic, spend, and conversion data come from Pinterest. The card joins page speed to the Pinterest revenue depending on that page. |
| Why both conditions | A slow page that still converts well is low priority. A fast page that converts poorly is a creative or offer problem, not a speed one. The pages that matter are slow AND under-converting: that is where speed is plausibly the cause of lost revenue. |
| Why Pinterest is special | Pinterest’s save-to-purchase cycle is long. A deferred buyer returns to your landing page weeks after the original save, often on mobile, often on a slower connection. If the page regressed since the save, the buyer you already paid to acquire bounces. The deferred click-through is uniquely fragile to speed regressions. |
| What good looks like | Core Web Vitals in the “good” band on mobile, and a conversion rate at or above the account average for Pinterest traffic. Pages that meet both never appear on this card. |
| The common cause | A page that was fast when the campaign launched degrades over time: a heavy hero image, a new third-party script, an unoptimised video, or a theme update. The Pin keeps sending traffic; the page quietly got slower. |
| Unit | Count of affected pages, with each page’s vitals and conversion-rate gap shown in the table. |
| Time window | 30D (30-day window, matched to Pinterest’s deferred-conversion behaviour). |
| Alert trigger | Any landing page with Largest Contentful Paint above roughly 4 seconds AND conversion rate materially below the account average for Pinterest traffic. |
| Sentiment key | pin_xc_landing_lcp |
| Roles | owner, marketing, engineering |
Calculation
Calculated automatically from your Pinterest Ads landing-page traffic joined to Core Web Vitals from your website performance connector. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading.Worked example
A UK home decor brand running Pinterest Ads to product and collection pages. Account currency: GBP. Account-average Pinterest conversion rate over the window: 2.4%. The 30-day window covers 02 May 26 to 31 May 26.| Landing page | Mobile LCP | Pinterest CR | vs account avg | Pinterest spend | Flagged? |
|---|---|---|---|---|---|
| /collections/spring-living | 5.8s | 0.9% | -63% | £2,100 | Yes |
| /products/velvet-armchair | 2.3s | 3.1% | +29% | £1,800 | No |
| /products/marble-coffee-table | 4.6s | 1.1% | -54% | £1,200 | Yes |
| /collections/lighting | 2.9s | 2.6% | +8% | £900 | No |
- Two pages are slow AND under-converting. The spring-living collection (5.8s LCP, 0.9% CR) and the marble coffee table page (4.6s LCP, 1.1% CR) are both far below the 2.4% account average. Together they carry £3,300 of Pinterest spend converting at roughly a third of the norm.
- The armchair page proves the point. It is fast (2.3s) and converts above average (3.1%). Speed is not its problem, and it correctly does not appear. The card isolates pages where speed is the plausible culprit, not every under-performer.
- Pinterest’s lag amplifies the loss. Much of the spring-living spend bought saves weeks ago. Those Pinners are returning now to a 5.8-second page and bouncing. You paid to earn the click-through; the slow page breaks it at the last step. On a fast-conversion channel the loss would be smaller because fewer buyers return late.
- The fix is engineering, not media. Pausing the Pin throws away the deferred demand you already paid for. The right move is to fix the page: compress the hero image, defer non-critical scripts, and re-measure. Then the deferred buyers convert as intended.
- Slow LCP + low CR + high spend = top priority, fix the page now.
- Slow LCP + average CR = lower priority; speed is hurting but not yet decisive.
- Fast LCP + low CR = not a speed problem; look at creative, offer, or price.
- Recently regressed LCP = find the change (image, script, theme) and revert or optimise it.
Sibling cards merchants should reference together
| Card | Why pair it with this alert |
|---|---|
| Pinterest Landing Page Performance | The broader landing-page view; this card narrows to the slow-and-under-converting subset. |
| Pinterest Landing Page Conv. Rate | The conversion side of the join; confirms how far below average a flagged page sits. |
| Pinterest Landing Page Revenue | Quantifies the revenue each slow page is putting at risk. |
| Pinterest Conversion Lag | Explains why deferred buyers return weeks later and why a speed regression after the save is so damaging. |
| Pinterest Wasted-Spend Burst (3-day spike) | High clicks plus zero conversions on a Pin often traces to a slow landing page flagged here. |
| Pinterest ROAS | Slow landing pages drag ROAS by breaking the final conversion step; fixing them lifts ROAS without changing spend. |
| Shopify Total Revenue | The commerce side; faster pages lift store conversion across all channels, not just Pinterest. |
Reconciling against Pinterest Ads Manager
Where to look in Pinterest Ads Manager: Pinterest Ads Manager > Reporting > Performance > review clicks, outbound clicks, and conversions per Pin and destination URL. Pinterest reports the click and the conversion but has no view of your page’s loading performance, that lives entirely in your website performance connector and tools like the Core Web Vitals field data or a lab test. This card is only possible by joining the two: Pinterest tells you which pages get paid traffic and how they convert, the performance connector tells you which are slow. Why our number may legitimately differ from Pinterest’s UI:| Reason | Direction | Why |
|---|---|---|
| Vitals are not in Pinterest at all | Different data source | Pinterest reports clicks and conversions only. The speed dimension comes from the website performance connector, so there is nothing in the Pinterest UI to reconcile the vitals against. |
| Field vs lab data | Either | Core Web Vitals can be measured from real-user field data or a synthetic lab test; the two can differ. The card notes which source drives a flag where it can. |
| Conversion rate basis | Small differences | The account-average comparison uses Pinterest-attributed conversions over the same window; a different attribution toggle in the UI shifts the conversion rate. |
| Deferred conversions | Ours accounts for lag | Because Pinterest conversions arrive late, a page’s recent conversion rate is still filling in; the 30-day window mitigates this. |
| Card | Expected relationship | What causes legitimate divergence |
|---|---|---|
website_performance Core Web Vitals | A page flagged here should show poor LCP in the website performance connector independently | Field data lags lab data; a recent fix may show as improved in lab tests before field data catches up. |
shopify.total_revenue for the page’s products | Fixing a slow page should lift store conversion for that page across all channels | Other factors (price, stock, seasonality) also move page conversion, so attribute improvement carefully. |