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Ads not converting? Did you check if you’ve run out of stock?
Many Shopify merchants overlook a major ad performance killer: out-of-stock products, on-site or in their Merchant Center feed.
Out-of-stock products, slow restocks, or mismatched product feeds can quietly burn your budget. And then disapproved ads and frustrated shoppers landing on sold-out pages all add up to a poor user experience and lost revenue.
We’ll walk you through how to align your inventory with your Google Ads strategy so you stop wasting budget and start seeing real returns.
The Link Between Inventory and Google Ads Performance
Inventory management and Google Ads are more closely linked than most Shopify store owners realize.
Google Ads, especially Shopping Ads, rely on product feeds submitted via Google Merchant Center to display products, prices, and availability.
These feeds pull real-time data from ecommerce platforms, such as Shopify. And any discrepancy between advertised products and actual stock can disrupt campaign performance in the following ways
- Ads for out-of-stock products may still run, leading to wasted clicks and zero conversions.
- Customers landing on unavailable items get frustrated and often abandon their carts
- For Local Inventory Ads, outdated data can even send shoppers to stores with no inventory, damaging trust and brand perception
- It also causes Google Merchant Center to flag or disapprove products, pause your ads, or lower your Quality Score, raising CPCs and tanking visibility
- Overselling is also a risk, leading to refunds, cancellations, and lost customer loyalty
- Even when stock is replenished, if your feed isn’t updated quickly, ads stay paused, costing you potential sales
In short, if your stock data isn’t accurate or up-to-date, your campaigns can’t perform, no matter how well they’re set.
Common Inventory-Related Google Ads Issues (and How to Fix Them)
When your inventory and Google Ads aren’t in sync, things break quietly but expensively.
Below are some of the most common issues Shopify merchants face and how to tackle them.
1. Inaccurate product feeds
An outdated product feed shows the wrong prices, availability, or product details. This causes misaligned ads and creates a disconnect between what users see in the ad and what’s actually on your site.
How to fix
Use tools like Google Content API for Shopping, Feedonomics, or Shopify’s native integrations to keep your product data synced in near real-time. Automate feed updates multiple times a day to avoid stale listings.
2. Out-of-stock products running in ads
Sometimes, your ads keep running even after a product sells out, and you’re paying for clicks that aren’t converting. This not only wastes your ad budget but also leads to customer frustration and missed conversions.
How to fix
Set up automated alerts to warn you when stock falls below a certain threshold.
Platforms like Prediko help monitor inventory levels in real-time and alert you before stockouts happen.
Also, create a script that regularly checks product pages for indicators of out-of-stock status (e.g., "out of stock" text). This should automatically pause the corresponding ads.
But prevention is better than reaction. To truly avoid stockout situations, factor in campaign-driven demand when forecasting inventory.
You can also start accepting backorders as a backup strategy. This keeps sales flowing while giving your team time to restock.
If you’re not sure where to begin, here’s a complete guide on how to set up and manage Shopify backorders.
3. Disapproved ads
Missing product data (like prices or availability), policy violations, or mismatched landing pages can get your ads disapproved, sometimes without you even noticing right away.
How to fix
Regularly review your Google Merchant Center Diagnostics tab. Fix flagged issues quickly and make sure your landing pages align with your ad content.
Double-check that all required fields (like GTIN, availability, and pricing) are complete and accurate.
4. Lost impression share
Even if your campaigns are well-structured, outdated inventory can limit ad delivery.
If Google sees you frequently promoting unavailable products, your impression share drops, which means fewer people even see your ads.
How to fix
Keep your bestsellers in stock and your feeds clean. Use demand planning tools to plan ahead for high-demand periods, and prioritize inventory for products with the highest campaign ROI.
Not sure which tools to use? We’ve reviewed the top 12 demand planning tools Shopify brands are using today.
Best Practices for Inventory Management While Running Google Ads
Running Google Ads without a handle on your inventory is like lighting money on fire.
Keep the following best practices in mind to make sure your ads and inventory work together.
1. Sync and track inventory in real-time for a proactive campaign strategy
Real-time inventory visibility is non-negotiable when you’re running Google Ads.
Your stock must be synced across Shopify, Google Merchant Center, and your inventory system to confidently run ads, knowing every product shown is actually available. It also enables faster decision-making.
Say a product’s selling fast, you can pause the ad, shift budget elsewhere, or plan replenishment before it becomes a problem.
2. Improve inventory forecasting with the right tools
Manual forecasting simply can’t catch up when your sales channels and ad campaigns move fast. To keep up with fluctuating demand, along with campaign and seasonal spikes, you need technology to do the heavy lifting for you.
Using tools like Google Ads Manager (GAM) for ad planning (kW planning, volume forecast) and Prediko for inventory forecasting allows you to align both sides of the equation: what you're promoting and what you’re actually able to fulfill.
Prediko, for example, pulls real-time sales data from your Shopify store and uses AI to forecast demand at the SKU level, factoring in trends, seasonality, and growth.
The app even lets you edit your demand plan to incorporate expected campaign spikes, so your purchasing and ad strategy stay aligned.
3. Set up low-stock alerts and reorder points
What if you could spot a stockout coming before your ads waste a single click?
Setting up low-stock alerts and reorder points helps you do exactly that. With these in place, you’ll know when to place your next PO based on lead times, safety stock, and sales velocity.
That means your high-performing products never go dark during a live campaign.
Shopify apps like Prediko let you set minimum and maximum days of cover, triggering alerts as soon as inventory drops below a safe threshold, so you can act fast and avoid wasting ad spend on products that can’t convert.
4. Organize products with custom labels
Not all products bring the same ROAS in your campaigns. That’s why you must group them intentionally.
In Google Ads, custom labels allow you to group products based on attributes like margin, seasonality, stock levels, or campaign priority, which can then be used to filter the products.
The grouping lets you tailor your bidding strategy, budget allocation, and messaging based on product performance and business goals.
Running low on a product? Pause the ad set or lower bids automatically. Just restocked a fast mover? Improve its visibility. This strategic organization translates into a higher ROAS.
5. Create separate campaigns for best-selling products and other products
Your bestsellers are proven performers; high-converting, high-demand, and often responsible for a big chunk of your revenue. Running them in the same campaigns as slow-movers can dilute performance and make it harder to optimize budgets.
This is why you must create separate campaigns for best-selling products so that you can give them the attention and budget they deserve.
You can increase bids, scale budgets faster, and monitor performance more closely. Meanwhile, your lower-priority or experimental products can live in separate campaigns with tighter controls.
This structure gives you cleaner data, smarter decisions, and better control over where your ad budget actually goes.
6. Coordinate inventory, marketing, and ops teams
Google Ads success isn’t just on marketing, it also depends on coordination across teams.
If your marketing team is planning a big Valentine's campaign but your inventory team hasn’t accounted for the spike in demand, stockouts are inevitable. And if your ops or purchasing team isn’t looped in, even they can’t plan purchases or logistics.
That’s why it’s important to create tight workflows between marketing, inventory, and operations.
Shared visibility into ad calendars, inventory forecasts, and supplier timelines helps everyone stay aligned, preventing disconnects that lead to wasted spend or missed sales.
Prediko bridges the gap between teams by giving everyone a shared view of demand forecasts. Marketing can easily edit the demand plan based on future promotions, inventory teams can plan with greater accuracy, and low-stock alerts allow timely purchasing.
Are You Inventory-Ready to Scale Google Ads?
Before you scale your ad budget, ask yourself
- Is our product feed syncing in real time?
- Are out-of-stock products automatically paused?
- Are we only promoting SKUs with healthy inventory?
- Are marketing, ops, and inventory teams aligned on priorities?
You can’t run high-performing paid ads on shaky inventory. With the right and synced setup, you’ll avoid ad disapprovals, reduce wasted spend, and convert more traffic
Start with accurate data, smart tools, and cross-team alignment.
