Let's assume an average marginal loss of 2% of gross sales to theft at a business with a net margin of 4% (typical of retail). Let's also assume wholesale markup of 50%, just to be conservative.

On two million in gross sales, a 2% loss equates to a $40,000. Assuming a 50% markup, the retailer has lost $20,000 in COGs. We'll ignore the other $20,000 for now.

On two million in gross sales, and a 4% net margin, the retailer can expect to make an annualized profit of $80,000.

We deduct the $20,000 in COGs loss, the retailer is now making only $60,000 a year, that's a loss of 25% in profit.

And that's using 50% markup.

In your stated case, with a 30% markup, the retailer would have lost $28,000 dollars in COGs, meaning the retailer is now making only $52,000, a reduction of 35% in net profits.

There is no universe in which this is a non-meaningful amount or to be dismissed as "well, something else has to be going wrong. Theft just isn't that big a deal."