Competitor stock availability monitoring: alert rules, tactics

Competitor stock availability monitoring tells you when rival sellers are in or out of stock on marketplaces and Google Shopping. Used well, it lets you win sales without simply dropping price. This page explains what to track, practical alert rules, smart reactions, and a 7-day playbook to get value fast.

What is it, in plain terms?

You track whether key competitors have stock for the exact same SKUs and offers on channels such as Amazon, Zalando, Cdiscount, OTTO, eBay, Bol, Allegro and Shopping ads. When they run low or go out of stock, you act: hold price, lift price within guardrails, switch promotion type, or increase exposure. When they come back, you revert.

When does this help most?

Peak periods: competitors burn through inventory and prices become volatile.
Long-tail SKUs: only a few sellers carry them, so stock gaps matter.
Brands with MAP/RRP: you need ways to compete that are not pure discounting.
Own fulfilment advantage: you can sustain an offer while others stock out.

Data you need before you start

Reliable product matching to the exact SKU or GTIN.
Competitor stock status or availability signal by channel and country.
Your cost, fees and returns so you can protect contribution margin.
Basic segmentation (brand, category, velocity) to target alerts.

Alert recipes that work

Trigger	Condition	Action	Why
Top competitor goes out of stock	We have 10+ units available	Hold price or raise by 1–3% within margin floor	Bank extra margin while you have the field
Two or more competitors low stock	Category is price sensitive	Reduce promo depth by 5% or swap to value-add bundle	Preserve price image without over-discounting
Competitor back in stock	We are priced +3% above them	Return to target price or re-enable price-match rule	Stay competitive when the market normalises
We are low on stock	Sell-through high in last 7 days	Pause discounts and lift price 1–2% within guardrails	Protect availability and contribution margin

Tactics by channel

Marketplaces: when rivals stock out, hold buy-box or winning offer with current price; consider a small increase if share and margin allow. Keep handling time honest to avoid penalties.
Google Shopping: increase bids for SKUs where key rivals are out, but cap CPC by expected margin. Test a small price lift when impression share rises.
Own site: use the window to sell bundles or higher-margin variants rather than blanket discounting.

7-day playbook

Day 1: pick one country and two channels. Choose 50–100 SKUs with clear competitor overlap.
Day 2: verify product matching and define “key competitors” per SKU.
Day 3: set three alerts: top competitor OOS, multi-competitor low stock, and competitor back in stock.
Day 4: add guardrails: minimum margin, floor price, MAP compliance and stock buffers.
Day 5: wire actions: price hold or small lift, promo depth change, bid adjustment on Shopping.
Day 6: review alerts, document exceptions, and fix edge cases.
Day 7: compare to a hold-out group and decide whether to scale.

How to measure impact

Price index vs rivals when they are out of stock versus when they are in stock.
Buy-box or winning offer share by SKU and channel.
Revenue and units for alerted SKUs versus control group.
Contribution margin after fees, shipping and returns.

Common mistakes to avoid

Acting on weak matches: false positives from poor product matching lead to bad decisions.
Overreacting: tiny, temporary dips do not always justify a price move.
Ignoring costs: add marketplace fees and returns when deciding on price lifts.
Breaking MAP/RRP: encode rules so you cannot breach them by accident.