Skip to content
Nebulus Systems

See what competitors stock — and when it sells out

We track competitor and marketplace assortments across your categories, monitor stock and availability over time, and surface the gaps in your own range — so you spot opportunities and stockouts before they cost you sales.

The problem

Assortments shift constantly: rivals add products, quietly delist others, and run out of stock at the worst possible moment. Spotting it by hand across competitors and marketplaces is impossible, so ranging and replenishment decisions get made on a partial, out-of-date picture of the shelf.

What you get

Decision-ready data

Not a tool to operate or a raw dump to clean up — structured, ready-to-use data, delivered the way you already work.

  • Catalog and assortment coverage by competitor
  • Stock and availability monitoring over time
  • New-product and delisting detection
  • Gap analysis against your own range

Use cases

What teams do with it

The same clean, reliable data powers very different decisions.

Range & assortment planning

Compare your range against competitors category by category, and find the products you're missing before a buyer does.

Stockout & availability alerts

Know the moment a competitor sells out — a window to win demand — or when a key line goes out of stock across the market.

New-product detection

Catch the products competitors add as they launch them, so you're never the last to react to a new entrant.

Delisting & long-tail decay

See what rivals quietly drop, a signal of weak demand or margin you can use to prune or double down on your own range.

Share-of-shelf tracking

Measure how much of a category each competitor covers over time, and where your presence is thinning.

How it works

From request to data in three steps

  1. 1

    Tell us what you need

    Share the competitors, sites, and data points that matter. We scope coverage, volume, and how you want it delivered.

  2. 2

    We handle everything

    We take care of the entire collection and quality process, end to end. Your team never operates or maintains a thing.

  3. 3

    You get decision-ready data

    Clean, structured data arrives on your schedule — via API, feed, your warehouse, or a dashboard.

What the data looks like

Your range vs. the market, over time

Every product mapped to your catalog, with availability and assortment changes tracked on each capture.

  • Your product / range mapping
  • Competitor & source
  • In stock / out of stock
  • Stock level (where shown)
  • First seen / last seen
  • New vs. delisted flag
  • Category & assortment tag
  • Captured timestamp

Why it's reliable

Coverage and accuracy you can trust

Keeping your data complete and correct is our job, not yours — even on the sources that block everyone else.

Complete market coverage

Every competitor, marketplace, and product that matters to you — tracked continuously, so nothing in your market goes unseen.

Local accuracy, worldwide

Prices and availability captured exactly as shoppers see them, in every market and region you sell in.

Even the hardest sources

We reach data behind defenses that block most collectors — so your coverage never has gaps.

Accuracy you can trust

Every record is matched to your catalog, normalized, deduplicated, and quality-scored before it reaches you.

FAQ

Common questions

How do you tell when something is out of stock?
We capture each product's availability exactly as a shopper sees it on every check, and track it over time — so you get both the current state and the full history of when items went out of and back into stock.
Can you track assortments across multiple marketplaces?
Yes. We cover competitor sites and the marketplaces that matter to you, including sources that block most collectors, and normalize everything into one consistent view of the shelf.
How do you match competitor products to my range?
We match on whatever identifies a product — your product IDs where you have them, or GTIN/UPC, brand, title, and attributes where there's no clean ID — then quality-score each match so gap analysis is reliable.
How often is availability checked?
On a cadence we scope to your category — from continuous intraday monitoring for fast-moving lines to daily or weekly where that's enough. You choose it; we maintain it.
We've tried monitoring this ourselves and it keeps breaking — can you keep it running?
That's exactly what we take on. Sources change, access gets cut off, and coverage slips — keeping assortment and availability tracking reliable on the hardest sites is a relentless, full-time job. We absorb all of it and simply deliver the data, so it never lands back on your team.
How is it delivered?
However you already work: a REST API, scheduled feeds, direct into your data warehouse, or a ready-made dashboard with change alerts.

Explore more

Other solutions

Pricing Intelligence

Know exactly what competitors charge. We track prices across sites and marketplaces and deliver the data on your schedule.

Learn more about Pricing Intelligence

Custom Market Data

Need data from specific sites? Tell us the sources and fields — we build the collection and hand you clean datasets.

Learn more about Custom Market Data

Delivery & Integration

Data lands where you already work — your API, scheduled feeds, your warehouse, or dashboards you can share.

Learn more about Delivery & Integration

Never miss a move on the shelf

Tell us the competitors and categories you care about. We'll track their assortment and availability and deliver it decision-ready.