This guide covers the 7 PPC metrics ecommerce brands should track weekly: blended ROAS, new customer CAC, cost per click trends, conversion rate, impression share, ad frequency, and budget pacing.
1. Blended ROAS (Not Platform ROAS)
Platform-reported ROAS is helpful for tactical decisions (which ad is working, which audience is converting), but it lies to you about the big picture. Both Google and Meta over-report conversions because their attribution windows overlap. A customer might see a Meta ad, search your brand on Google, and buy. Both platforms claim that sale.
Blended ROAS cuts through the noise: Total revenue (from Shopify) / Total ad spend (across all platforms)
Track this weekly. The trend matters more than the absolute number. If blended ROAS was 3.5x last week and it's 3.1x this week, something shifted. Maybe CPCs went up. Maybe a top-performing creative fatigued. Maybe your conversion rate dropped. The blended number is your early warning system.
A common mistake: only checking blended ROAS monthly. By the time you catch a problem in a monthly review, you've already wasted 2-3 weeks of budget. Weekly checks catch issues before they compound.
What's a good blended ROAS? That depends entirely on your margins. If your gross margin is 65%, you need roughly 2x blended ROAS to break even after COGS, and 3x+ to be profitable after operating costs. Use your specific margin to set your target, not someone else's benchmark.
2. New Customer CAC
ROAS tells you how much revenue your ads generated. CAC tells you how much it cost to acquire each new customer. These are different things, and you need both.
Calculate it weekly: Total acquisition ad spend / New customers (from Shopify customer reports)
Why weekly? Because CAC spikes can hide inside a decent blended ROAS. If your ROAS looks fine but your new customer mix is dropping (more repeat buyers, fewer new ones), your ads are maintaining revenue but not growing the business. You're churning through your existing customer base instead of expanding it.
Track the trend. If CAC was $35 last month and it's crept up to $42, investigate. Common causes: creative fatigue on Meta (your best ads stopped working), increased competition on your keywords (Google CPCs went up), or seasonal effects (some months are just more expensive).
Compare your CAC to the industry benchmarks we published separately. If you're significantly above the median for your category, that's a signal to dig deeper.
3. CPC Trends by Campaign
Don't just check your average CPC. Check the trend by campaign type. Rising CPCs on branded search mean different things than rising CPCs on non-branded search.
Branded CPC rising: A competitor might be bidding on your brand name. Check your auction insights report. If a new competitor appeared, you may need to increase your branded bid to maintain position.
Non-branded CPC rising: This usually means more competition for your keywords. Could also mean your Quality Score dropped. Check the Quality Score column for your top keywords.
Shopping CPC rising: Often seasonal. But also check if your product feed quality has declined, because poor feed data leads to worse placements at higher costs.
Meta CPC rising: Usually creative fatigue. When your audience has seen the same ad too many times, CTR drops, and Meta charges you more per click. Time to rotate in new creative.
The action threshold: if CPC is up more than 15% week-over-week on any campaign type, investigate immediately. Small increases (5-10%) are normal noise. Larger jumps mean something changed.
4. Conversion Rate by Landing Page
Most brands track conversion rate at the campaign level. That's okay, but it misses the landing page dimension. The same ad can perform very differently depending on where you send the traffic.
Check your top 5-10 landing pages weekly. Look for pages where conversion rate dropped versus the previous week. A sudden drop usually means something broke (a page error, a slow load time, a missing product image) or something changed on the page (new content, a price change, removed social proof).
Benchmarks for ecommerce landing page conversion rates:
| Page Type | Good CVR | Great CVR |
|---|---|---|
| Product page (from Shopping) | 2.5-3.5% | 4.5%+ |
| Collection page (from Search) | 1.5-2.5% | 3.5%+ |
| Homepage (from branded) | 3.0-4.5% | 6%+ |
| Landing page (from Meta) | 2.0-3.0% | 4%+ |
If a page consistently converts below these ranges, it's worth A/B testing the headline, hero image, price display, or social proof. Conversion rate improvements are the single fastest way to lower your CAC because they work across every traffic source.
5. Search Impression Share
Impression share tells you what percentage of available impressions your ads are capturing. If your branded impression share is 85%, that means you're missing 15% of searches for your own brand name. Someone else is showing up (or nobody is showing up) for those queries.
Weekly checks you should make:
- Branded impression share: Should be 90%+ at all times. If it drops below 85%, increase your branded budget or bids. Missing branded searches is the most expensive mistake because these searchers are the most likely to convert.
- Non-branded impression share: Usually 30-60% for competitive keywords. Track the trend, not the absolute number. If it's dropping while your budget is the same, competition increased.
- Lost IS (budget): This tells you how many impressions you missed because your budget ran out. If it's over 20%, you're leaving money on the table. Either increase budget or tighten targeting to focus spend on better-converting segments.
- Lost IS (rank): This tells you how many impressions you missed because your Ad Rank was too low. Fix this with better Quality Scores or higher bids.
Impression share is an underrated metric. Most brands obsess over ROAS and CPC but ignore whether they're even showing up for the searches that matter. A quick audit can reveal where you're losing impression share and why.
6. Ad Frequency on Meta
Frequency measures how many times the average person in your target audience has seen your ad. On Meta, this is a critical metric because creative fatigue sets in fast.
General guidelines:
- Prospecting campaigns: Frequency above 2.5 usually means fatigue is starting. CTR drops, CPC rises, and conversion rate declines. Time to rotate creative.
- Retargeting campaigns: Frequency can go higher (4-6) because these people already know your brand. But even retargeting ads fatigue eventually.
- Advantage+ campaigns: Check frequency at the creative level, not just the campaign level. Meta might be over-serving your best-performing ad to the point of fatigue.
When frequency climbs above threshold, the fix isn't to lower your budget. The fix is to introduce new creative. Have 3-5 ad concepts in rotation at all times, and plan to replace at least one per week. Brands that produce more creative consistently outperform brands that run the same ads for months.
Track frequency weekly for each active ad set. Plot it against CPC and conversion rate. When frequency rises and performance drops in the same week, that's your fatigue signal.
7. Budget Pacing and Spend Rate
This one sounds basic, but a surprising number of brands don't track it. Budget pacing tells you whether your campaigns are spending at the rate you intended.
Underspending: If a campaign is only spending 60% of its daily budget, something is wrong. Either your targeting is too narrow, your bids are too low, or your ads aren't getting approved. Underspending means you're missing opportunities.
Overspending: If you set a monthly budget of $10K but you're on pace to spend $14K, your daily budgets might be set too high, or Google/Meta's daily budget flexibility (they can spend up to 2x daily budget on any given day) is kicking in more than expected.
Weekly budget pacing check: compare actual spend to date vs. planned spend to date. If you're more than 10% over or under, adjust. Over-pacing means you'll run out of budget before month-end (and your best-performing days might get cut short). Under-pacing means you're leaving conversions on the table.
Also check spend distribution across campaigns. If one campaign is eating 60% of the budget but only generating 30% of conversions, rebalance. Move budget toward the campaigns with the best ROAS and tighten the ones that are over-indexing on spend.
A monthly review of spend vs. results by campaign type can reveal patterns that weekly checks miss. Set a calendar reminder to do a deeper budget review on the first Monday of each month.
Frequently Asked Questions
Check blended ROAS, CPC trends, and budget pacing weekly at minimum. Check conversion rate and impression share weekly. Check creative frequency on Meta 2-3 times per week. Monthly, do a deeper review of CAC, LTV trends, and campaign-level profitability.
Blended ROAS (total revenue / total ad spend) is the most important single metric because it cuts through platform attribution overlap. But you also need new customer CAC to know whether you're actually growing, not just re-converting existing customers.
It depends on your gross margin. Take your gross margin percentage, subtract 15-20% for operating costs, and the remainder is your breakeven point. If your margin is 60% and operating costs are 18%, you need 2.4x blended ROAS to break even. Target at least 1.5x your breakeven ROAS for healthy profitability.
Check impression share first. If you're losing more than 20% of impressions to budget or rank, you're leaving opportunities on the table. Then check Quality Score. If most keywords are below 6, your ads are costing more than they should. Finally, compare your CPC and conversion rate to industry benchmarks.
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