Check https://www.blackhatworld.com/forums/bhw-marketplace-rules-and-how-to-post.203/ , to see if your service can fit into the Marketplace. If yes, then once you’ve been a member for 60 days and built your posts up to a grand total of 100 (or more, if you’ve got a lot to contribute), you’ll be eligible to upgrade to Jr VIP status OR if you don't qualify for Jr. VIP but still want to submit a thread onto the marketplace then Marketplace seller upgrade could be possible. That would help towards finding users or rather buyers for an eligible product or service.