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.
Step 1 is handing money over to these guys I'm gonna take a wild guess that there is no escrow protection there so Step 2 is these guys actually putting your ad up once they have your money, then Step 3 keeping your ad up for the views they promise. God be with you.