When building affiliate links for your website, should they be related to your website's target audience or no? like say for example your website is a movie site, should you accept affiliate requests from sites that are also movie sites?
Did you mean affiliate link or actual link? Your question seems a bit confused anyway. - If you did mean affiliate link - Why not? Didn't you just created the site for targeted audience? Most of your traffics will be converted easily if you offer something they do really wanted or looking for. - If you did mean actual link, like link exchange or a scheme - It is depends on the quality of website asking to exchange a link with you. You have to be selective or you would feel a pain later.
You only want relevant links or affiliate links... How about we look at it this way... Lets say you have a website about "How To Make Money Online" and someone asks you if they can put their porn link on it? What are you going to say then? I think that's an obvious answer.. Now, if they have a link that is associated with "How To Make Money Online With Porn", well, I will leave that up to you.
Yes, your link has to be related to the content of the site. Do some research and you will be surprise by the number of sites that will be related to yours.