How to test demand before buying large stock

Feb 1, 2025

Why Demand Testing Matters for Resellers

Jumping into bulk purchases without knowing if your products will actually sell is one of the biggest risks new resellers face. Testing demand before investing in large stock helps you protect your capital, avoid waste, and build a smarter, more sustainable business. Here’s a straightforward guide to test product demand, even if you’re just starting or working with a small team.

Step 1: Research and Identify Potential Products

Before you even source a single item, spend some time researching what products are trending or consistently sell on platforms like eBay, Mercari, Facebook Marketplace, or niche-specific sites. Search for similar listings and filter by sold items—these show actual demand, not just hopeful sellers.

  • Look for products with multiple recent sales (in the last 30 days).

  • Check price consistency: Are items selling for predictable amounts?

  • Scan listing quality: What do top sellers do differently in their photos and descriptions?

Tools like Terapeak (for eBay) and Mercari Trends can help you analyze what’s hot.

Step 2: Start Small—List Before You Buy in Bulk

Never commit to a large purchase until you’ve validated real interest. Here’s how to test demand with minimal risk:

  • Source a small quantity (or one item) first. You can buy from local stores, thrift shops, or even use items you already own.

  • List on multiple marketplaces to maximize exposure. For example, list on both eBay and Facebook Marketplace to see where interest is strongest.

  • Monitor the response:

    • Are you getting views, watchers, or messages?

    • How quickly does the item sell?

    • Did you have to discount to make the sale?

Keep track of your results. If the item sells quickly and at the price point you want, that’s a good indicator of demand.

Step 3: Use a Centralized System to Manage Listings and Inventory

As soon as you’re listing the same product across more than one marketplace, you need a simple way to keep your inventory and listings in sync. This prevents double-selling and confusion, especially if you decide to scale up later.

  • Try a central inventory system: Simple spreadsheets work for very small operations. For more automation, platforms like Gavelbase allow you to sync inventory and listings across multiple sales channels, track sales, and avoid overselling.

  • Update stock counts as soon as an item sells on any platform.

  • If you have a team, assign one person to update the inventory so nothing slips through the cracks.

Step 4: Assign Basic Team Roles (if you have help)

If you’re working with friends, family, or a small team, defining roles early prevents confusion:

  • Sourcing: Who finds and buys products?

  • Listing: Who photographs and writes descriptions?

  • Inventory management: Who tracks stock and updates listings?

  • Shipping/Pickup: Who packs and ships orders, or coordinates local pickup?

Even if you’re solo now, planning for roles makes it easier to delegate as you grow.

Step 5: Track Sales, Fees, and Buyer Feedback

Profit isn’t just about the sale price. Consider all costs:

  • Marketplace fees (eBay, Mercari, etc.)

  • Shipping fees or supplies

  • Time invested (if you’re spending hours listing, is it worth it?)

Keep a simple record of each sale, what you paid for the item, what it sold for, and your net profit. Spreadsheets or inventory management tools (like Gavelbase) can make this process smooth and transparent. Don’t forget to review buyer feedback—compliments and complaints both teach you what sells best and what to improve.

Step 6: Handle Shipping and Pickup Cleanly

Reliable fulfillment builds your reputation and helps you gauge if handling more volume is realistic:

  • Ship fast—buyers expect prompt delivery.

  • Use tracking numbers to avoid disputes.

  • For local pickup, coordinate safe, convenient meeting spots. Use cashless payment apps if possible.

  • Document every transaction (who bought what, when, and how it was delivered).

Doing this well in your test phase will make scaling up much easier later.

Step 7: Review Your Results and Decide

After you’ve sold a handful of test items, review your data:

  • Did the product sell quickly and at target profit?

  • Was managing inventory and fulfillment smooth?

  • Did you get positive feedback?

  • Are you comfortable handling more volume?

If the answers are yes, you can move forward with more confidence and consider buying larger stock. If not, tweak your approach or try a different product—small tests save you from big mistakes.

Bonus: Additional Tips for Beginners

  • Start with low-risk items: Avoid perishable or highly seasonal goods until you’re experienced.

  • Track everything: Data-driven decisions beat guesswork every time.

  • Stay organized: Messy inventory or finances quickly lead to problems—use tools early, not just when you’re overwhelmed.

Resources

Testing demand before you buy large stock isn’t just safer—it’s smarter. With these simple steps and the right tools, you’ll know exactly what to invest in, keep your operations under control, and build a business that grows by design, not by luck.