OK, now this may seem obvious, but really, I've seen so many dating sites that are just outright generic. It is so important to establish a professional image. This includes your logo and your template choice. If you choose a niche like sci-fi lovers, it's also fun to use a theme like the solar system or stars. Just make sure your site looks super-professional. Branding is going to set you apart from other dating sites that may provide the same niche as you. Branding is what will establish you as an authority site.
This isn’t to scare you off. I simply want you to know that this guide is going to focus solely on ways to make real, sustainable extra income online. Not just a few bucks. I want to share all the mistakes I've made that got me to where I am now so that you don’t have to go through them, and can build a successful online source of income for yourself.
Offer crazy guarantees: "Find your soulmate in SIX MONTHS or we'll give you a free [offer here]". There's two possible outcomes: One is that your membership base will grow in those six months, and the probablility for any member to "find their soulmate" will increase. The other possible outcome is that they will not find their soulmate, and you simply give them what you offered for free. If you're smart you may simply offer something that they will get for free anyway, but is hard to find, such as an affiliate deal where you even get a commission for offering free stuff to your members (such deals can be found in various affiliate networks).