How to create a website that sells twitter followers, facebook likes, youtube views etc?

Do you mean “selling” or “sharing”?
Ya know, the links at the bottom of the page, saying: “Share this page”.
I’ve never seen anyone literally selling Facebook, for instance; don’t even think you can. Do you also mean, having an ad on the side of the page, on Facebook? Or, do you mean attracting visitors to follow their feed(s)? Can you give examples of sites that do this? There are a bunch of web-developers on Fluther who might be interested in knowing.

What he is talking about is actually buying Twitter followers, as in you pay a person some money and your Twitter page gets a couple hundred more followers.

The important part is that the service does not attract people to follow you, because the new followers aren’t actually real people. They are just a bunch of “bots” that artificially inflate your number of followers and make the page seem more popular than it really is.

Any kind of website that can get them. Good luck on your endeavors

You’re better off engaging as many people as you physically can on FB, Twitter, and the like. Engage them with content they care about and ask them to follow you.