Can you integrate with anything that is already frequently used (ala Salesforce or Zendesk)? Do you have a unique application for a specific industry that you can document? I saw someone said run Google or Facebook ads - hard to argue with that. But to get your first 10 paying customers you probably need to go the organic route. I would leverage an SEO strategy where you barnacle on highly adopted platforms - think Quora, Medium, or even Facebook Groups or LinkedIn Groups.