we do not share your data with anyone and there are many ways to control the visibility and storage life of your data here.
but the internet is a public space and you should always assume your data could be compromised.
be smart with your password, use tor or a vpn, and use pgp for sensitive communications.
In order to increase your sales on LB, I’d recommend interacting with the people on LB first so that people can get to know you more and can trust you, as well as building up your reputation by joining in on topics. If you’re well known from the dark net and are a reliable source, people will find out soon enough and customers from there might also be on LB. other than that I’d just say make sure to have high quality products with good photos and good descriptions because it comes a long way.
New buyers arent a bad thing but they have a lot of potential downside in this particular situation. Someone might make multiple accounts just to get free stuff, someone might never have the means to buy something (no card or way to get bitcoin), someone might be willing to throw away their dispute record etc.
A qualified buyer is much more likely to become a real customer and has more influence in recommending you and is vested in working with you if their is a problem in order to maintain there reputation.