Selling in More Than One Place Without Doubling the Work

Selling in more than one place is sensible. Doing it by typing everything out again for each site is what makes people give up on it by the third week.

Write the item once

The description of what a thing is does not change between sites. Only the framing around it does. If you are rewriting the item itself each time, you are doing the same job repeatedly and you will eventually do it inconsistently, which is worse than not doing it at all.

Keep one version true

The real cost of duplication is not the typing. It is the day you change a price or a detail in one place and forget the others, and a buyer finds the old version. One version to correct is the whole argument for keeping listings in a single place and pushing them out.

Let the audiences differ

What should change per site is the framing and the tone, because the people are different. What should not change is the item, the price and the postage terms.

Two done properly beats four half done

A neglected shop on a fourth site is not extra reach, it is a shop with old prices and no replies, which is an advert against you. Add the next one when the current ones are actually being run.