Test a product idea by selling interest first, not inventory first. Create a simple landing page or Amazon-style listing mockup, run a small ad campaign, and see whether people click, sign up, or try to pre-order.
If people only like the post but do not take action, the idea is weak. If they join a waitlist, ask for more details, or place pre-orders, that is a much stronger sign of demand.
You can also test with a small batch, limited launch, or crowd-funded pre-launch instead of ordering full inventory. For Amazon sellers, the safest method is to validate demand with search data, competitor listings, and a tiny test order before scaling.
The goal is simple: prove demand cheaply before you commit money to stock.
