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Inventory Planning for Vape Retailers: Stock Depth vs Range Breadth

By ONEWING GROUP LIMITED · Updated 2026 · Reading time: 7 min

Every vape retailer faces the same inventory question: stock deep (more units of a proven SKU) or stock broad (more SKUs across a range). The wrong answer is expensive — deep stock of a slow mover ties up cash; broad stock of unproven SKUs generates dead inventory. This is the planning framework, stated for trade buyers who need the maths.

The depth-versus-breadth trade-off

Depth means more units of fewer SKUs: the shelf holds 40 units of one proven device rather than 10 units of four devices. Depth’s advantage: the proven SKU sells through, the margin is predictable, and the cash flow is steady. Depth’s risk: if the SKU fails (a supply disruption, a compliance change), the shelf has nothing to fall back on.

Breadth means more SKUs of fewer units each: the shelf holds 10 units each of four devices. Breadth’s advantage: the shelf covers more customer profiles and hedges against any single SKU’s failure. Breadth’s risk: unproven SKUs generate dead inventory, and the cash tied up in slow movers is cash not earning its keep. The right answer is a portfolio — depth where the evidence supports it, breadth where the customer base demands it.

How to calculate sell-through rate

Sell-through rate is the percentage of received stock that sells within a defined window (usually 30 days). The formula: (units sold ÷ units received) × 100 = sell-through %. A device that sells 30 of 40 received units in 30 days has a 75 per cent sell-through — a proven mover worth stocking deep. A device that sells 5 of 40 has a 12.5 per cent sell-through — a slow mover worth de-listing or reducing to a single facing.

The trade translation: sell-through is the evidence that drives the depth-versus-breadth decision. Stock deep where sell-through exceeds 60 per cent; stock broad where it is between 30 and 60 per cent; de-list where it falls below 30 per cent. The maths is the inventory strategy, not a guess.

Safety stock and reorder points

Safety stock is the buffer that prevents a stockout during the supplier’s lead time. The formula: safety stock = (maximum daily sales × maximum lead time) − (average daily sales × average lead time). For a device that sells 2 units per day on average (peaking at 4) with a 7-day average lead time (peaking at 10): safety stock = (4 × 10) − (2 × 7) = 40 − 14 = 26 units.

The reorder point is the stock level at which a new order is placed: reorder point = (average daily sales × average lead time) + safety stock. For the same device: (2 × 7) + 26 = 14 + 26 = 40 units. When stock falls to 40, order more — and the maths prevents both stockouts and overstocking.

How the HERC’s focused range simplifies the decision

The HERC’s range is built for depth: a focused set of profiles on one engineering platform, so every SKU behaves identically and the shelf can stock deep without the breadth risk. A counter that stocks 40 units of the HERC in two flavours (menthol + fruit) has depth on a proven platform — and the sell-through evidence will confirm whether to deepen further or add a third flavour.

The honest positioning: the HERC is the depth play. A shelf that stocks the HERC deep plus one or two breadth SKUs (a flexibility device, a lower-tier option) has a portfolio that covers the market without the dead-inventory risk of a sprawling range. Our MOQ guide and margin calculator cover the commercial maths that supports the decision.

Inventory Planning Formulas

Frequently Asked Questions

Should a vape retailer stock deep or broad?

Both, as a portfolio. Stock deep where sell-through exceeds 60 per cent (proven movers worth the cash commitment); stock broad where sell-through is 30 to 60 per cent (customer coverage with controlled risk); de-list where it falls below 30 per cent (dead inventory). The HERC’s focused range is built for the depth play.

How do I calculate sell-through rate for a vape device?

(units sold / units received) x 100, measured over a 30-day window. A device that sells 30 of 40 received units has a 75% sell-through — a proven mover. A device that sells 5 of 40 has 12.5% — a slow mover. The rate is the evidence that drives the depth-versus-breadth decision.

What is safety stock and how much do I need?

The buffer that prevents a stockout during the supplier’s lead time: (max daily sales x max lead time) - (avg daily sales x avg lead time). For a device selling 2/day (peak 4) with a 7-day lead (peak 10): safety stock = 26 units. The reorder point is (avg daily x avg lead) + safety stock.

How does the HERC simplify inventory planning?

Its focused range is built for depth: one engineering platform, consistent behaviour across flavours, so the shelf can stock deep without the breadth risk. A counter with 40 HERC units in two flavours has depth on a proven platform — and the sell-through evidence confirms whether to deepen or add a third flavour.