Fonts For Affiliate Site?

Arial.

I think this is very good question! Having a great font for your site can visually make the influence that the site is credible and trusted. So choose the fonts according the topic and theme of the site. Just don't go too fancy! Remember that the readability is essential. If its hard to read, people will go away (and not through your aff links lol)

Check out fontpair dot co site shows you commonly paired aesthetic fonts that the big sites use.

HELVETICA