I have an idea for a website that will attract many visitors.
I will need to put a lot of effort to build it,
but then it will run (almost) by itself.
What will be the best way to convert it to some passive income?
Advertising? Affiliates? VIP registration?
How much should I expect to earn from it?
it will be depend with your traffics mate i understand that advertisement is the best ways to earn so gathering your target visitors will make your site to have passive earnings, i think if you are just starting some mellow ads and a-ads can only give you smalle arnings but in due time when adsense been added you can't count your earnings anymore. hehehe good luck