If I have a small eBay online business that I run as a hobby and not for essential parnasa am I allowed leave the listings up over the nine days or do I need to take them down (it’s definitely some level of hassle to pull them down and put them back up). Also it is not guaranteed that someone will actually buy something from me during the 9 days even if I do leave the listings up. If I am allowed to leave the current listings up am I also allowed to add new listings or should I wait for those until after Tisha b’av?
You do not have to take the site down. The idea is that during the nine days we minimize our involvement in business, however there is no issue with keeping the site open, as you aren’t doing anything. You should however wait until after the nine days to put up new listings if possible.
O:CH 551-2, M:B 551-11, Poskim.