How We Check Our Tools and Sources

Start with a useful question

We prioritize questions sellers search for and tasks they repeat in their work. A page should make clear what it helps you decide after the calculation, with a usable tool and a worked example.

Make the method and evidence visible

• Sources: for information that changes or depends on conditions, such as tax, payouts and shipping, we use primary sources from government bodies, platforms and carriers where available.
• Calculations: we explain units, formulas, rounding, assumptions and exclusions. We do not set an unverified value as a platform’s official rate.
• Independence: we disclose advertising or partnership relationships and do not change calculations or editorial standards to suit them.
• Updates: we revisit relevant pages when policies or fees change and record corrections that could affect a reader’s decision.

AI may help organize source material and prepare drafts. Figures, sources and the decision to publish are checked separately. Calculations are planning aids; where applicable, compare them with actual platform statements and customs or tax conditions.

Language and scope

The English edition includes the text counter, unit converter, time zone meeting planner, bulk title checker and these site-information pages. The rest of the tool catalogue and seller news currently use Korean. Translating an explanation does not expand a rule to another market or product category. For example, an Amazon.com title rule remains an Amazon.com rule.

For units and time zones, we identify the definition and technical reference used, and explain when a result depends on information built into your browser. A source link does not mean that the tool fetches the latest source data on every use.

If you find a problem, send us the page and evidence. Our correction policy explains what happens next.