There is no best channel — there is a channel that matches your product, your volume and how much verification you are willing to do yourself.
What each one selects for
- Alibaba — companies that invest in selling to foreigners. Good English, export experience, and a margin that pays for both.
- 1688 — the domestic market. Lower prices, little English, and no assumption that you are a foreign buyer. Harder, and closer to the real cost.
- Trade shows — companies with a marketing budget and something to show. Excellent for calibrating a category quickly, weak for depth.
- An agent or representative — a filter that has already done the qualification. You pay for judgement rather than for access.
The practical approach
Use two channels at once. Platforms give you a price floor and a sense of the category; a visit or an agent tells you which of those prices is real. Relying on one channel alone is how a quote that looks excellent turns into a sample that is not the product you specified.