The most common mistakes

Running ads before understanding the basics. Without knowing your margins, your customer, or what you’re measuring, every ad is a guess. When sales stop, you can’t tell why.

The common thread: doing things without knowing why. Here’s how to avoid that.

1. Know your numbers

Before you spend a dollar on ads, you need to know, per product:

  • Your cost from Randmar, plus shipping

  • Your gross margin after cost of goods

  • Your average order value across the store

  • Your break-even ad cost: how much you can spend to get one sale and still not lose money

  • Your fixed costs: apps, subscriptions, software. They add up faster than you think.

Margins can vary a lot from one product to another. That alone should decide which products you push in ads and which ones you don’t.

Then keep watching. Cost of goods, ad spend and subscriptions can slowly squeeze your cash even when sales look good. Check your numbers weekly, not only when something feels off.

2. Know your customer

If your customer is “everyone,” your customer is no one.

Get specific: who buys, roughly how old they are, whether they buy for themselves or as a gift, and when in the year they buy. Two buyers of the same product can want very different things and respond to very different messages.

The best way to learn this: call your customers. Don’t ask how they feel about the product. Ask what they actually do with it. Their answers will change how you write your ads and product pages.

3. Set up the business properly

Boring, but non-negotiable. Do it before launch, not after your first sale:

  • Register your business and get your sales tax numbers (GST/QST in Quebec)

  • Open a separate business bank account and card. Mixing personal and business money makes taxes a nightmare.

  • Write your policies: returns, shipping times, free shipping threshold, who pays for what when something goes wrong

  • Keep your files organized: product photos, invoices, supplier info, one folder per product

Ad platforms and marketplaces will ask for proof your business is real. Having it ready saves you weeks of back-and-forth.

4. Make your tracking work before you spend

If your tracking is wrong, every decision you make on top of it is wrong too. You won’t know which ads actually bring in sales.

Before you turn on ads, place a test order and confirm that:

  • Each purchase is counted once, not twice

  • The real order value is sent, not a placeholder

  • The numbers in your ad platform roughly match the orders in your store

Double-counted purchases and broken conversion tags are common. When they happen, your ads look better on paper than they really are.

5. Build your operation with Randmar

Randmar handles the warehouse and shipping. That frees you up, but you still own the customer experience. A few rules worth following:

  • Know your rep. A good relationship with your Randmar contact is worth more than any app. Ask questions early.

  • Check stock before you advertise. Don’t spend money sending people to products that can’t ship.

  • Pull product data by SKU. It’s the most reliable way to get accurate info into your store.

  • Resolve with Randmar first, then talk to the customer. For returns, damaged items or replacements, get confirmation before you promise anything. Never promise what you can’t guarantee.

  • Plan ahead for busy seasons. Talk to Randmar about stock before the holidays, not during.

Your pre-launch checklist

  • Cost, margin and break-even ad cost for every product

  • A clear picture of my main customer (or two)

  • Business registered, tax numbers, separate bank account

  • Return and shipping policies written

  • Tracking tested with a real order

  • Stock confirmed with Randmar

Last thing

You don’t need everything perfect before you launch. You need to know what you’re doing and why.

Do the groundwork, launch, then keep learning from your numbers and your customers.