Create a 1 minute video about your service and post it onto Youtube. This can either be a screencast or a webcam video of yourself talking about your service.
Most companies do not use Youtube as a primary acquisition channel. Youtube is actually one of the best channels for promotion, and it's very easy to get feedback and traffic. However, while videos are super effective, going viral is difficult. The trick here is just like creating blog content. You want to name these video with the right keywords.
Production quality is not that important in this case.
1. 10 seconds - short and powerful pitch - Tell them why they should use it. What's the problem? UVP would be great.
2. 10 seconds - Tell them what your solution is.
3. 30 seconds - Talk about 3 of the key features and how you plan to deliver the result.
4. 10 seconds - Talk about the grand vision or your startup's mission.