Finding a topic is not that hard but it does require some research. That is always the most important first step in any business venture. If you don't know what else is out there, how can you compete? How can you improve on an existing model?
Finding Your Topic
Start with what you know. English teachers always tell you to write what you know. That philosophy goes for business as well. If you are interested in fitness, begin your research there. Are there other membership sites on the topic of fitness, nutrition or both? If there is, find out what makes them stand out.
Within each topic there is room to move around. You can choose a niche within that general topic (fitness for example) to specialize your membership site. Maybe the site will offer fitness tools for women or men's fitness. One advantage that your niche membership site would have is a more focused approach to fitness for that particular gender.
Choosing Your Price
What is it about $0.95 or $0.99? It's almost as if people are saving a lot with only a few cents. Someone is more likely to pay $9.95 than $10.00. It must be a psychological thing but it works. Knock off a few cents and you are in business.
Your price will depend on two things: competitive prices and your offerings. If another fitness site offers membership for $9.99, you will have to have something spectacular if your price is higher. And, that might be possible if they offer the basics for their members. Choose membership tools that make life easier for your potential members.
Testing the Waters
If you already run a website or a blog, use that forum to gauge how much interest there is in your niche topic. Poll visitors; send survey links to customers and post engaging blog entries that beg feedback on your possible new enterprise. You don't want to sink money into a venture that won't even get off the ground.
Want to start a membership site that will make you a profit? Research topics for your site and explore niche possibilities that will bring you the traffic and the money. But, when you find a worthy niche, you will see a recurring income each month from your hard work.