Take it seriously. Yes, you’re applying for an online job. Yes, you can do the work in your underwear, but that doesn’t mean it’s not a “real job”. You must treat it as such or they aren’t going to treat you as a serious candidate. You aren’t the only one who wants to work in their underwear. In fact, the competition online is likely higher than it is in your local area.
An affiliate marketing program is a lot of work, and in most situations there's a lot of competition so you're not going to be bringing in money immediately. Business owners and entrepreneurs suppose that all you need do is setup a site and choose an affiliate to associate with and then just let it run its course. But according to Three Ladders Marketing, only 0.6% of affiliate marketers surveyed have been in the game since 2013. That means that affiliate marketing takes time and effort to build and make money.
You'll also need ecommerce software, fulfillment software, worry about warehousing, customer service, refunds and so on. But that's not all. You'll also need traffic. Think search engine optimization, Facebook ads, and other social media campaigns. Sound like a lot of work? Sure, it is. Especially if you do it all on your own. You could opt for Amazon's platform, which might be the easier route. But, then again, at the end of the day, this is a serious business, which could produce significant profits. So you're either all in or you're not.