Yes you can earn lot of money using affiliate marketing. Shoutmeloud an Indian blog earns lot from affiliate. The blog refers bluehost links, hostgator etc links. So yes you can earn money by offering coupon code of those website.
Nearly all of our affiliate traffic is coming from these types of websites. Based on commissions we pay, and considering they are promoting hundreds of other providers, I imagine one could make a decent living with this type of business.
Everything is possible! You might want to firstly think of your site's name, domain, hosting, SEO and the coupons themselves. I guess then you might need a template for some kind of coupon site. You can learn about some HTML coupon site templates here and about 15 best coupons site WordPress templates over here.