Now, make a list of what you're missing. Not what you want—what you actually need to fill gaps.

• Do you have a mesh option for every device you carry? If a device only has standard coils available, that's fine, but know that you're limiting flavor-focused customers.
• Do you have a budget coil for entry-level devices? Not everyone wants to spend $12 on a pack of mesh.
• Do you have coils that suit high-wattage users? Some customers push their devices hard. Make sure you've got something that won't burn out in a day.

Keep this list short. You're not trying to stock every coil under the sun—just the ones that fill a real need.