If you have built up an email list, you could also promote your affiliate offers via email promotions. Just make sure you build up a relationship with your audience first instead of going for the hard sell straightaway. The emails you send out must contain your affiliate links to products so when your audience click through. the sale is attributed to you.
As Target is the second-largest general retailer in the United States, their affiliate program is primarily for American bloggers or publishers who can route visitors to relevant products. Overall, the program works much like Amazon’s does in that publishers (bloggers) get a small commission on sales, but Target’s gigantic product base (over one million items) and high brand recognition make their affiliate program a great option for influencers.
The topic you choose must have enough depth that you can create a lot of content for it. This is important for building an authoritative site, for search engine optimization, and most importantly, for the end user. If you don't have enough content about a topic, you're not going to be taken very seriously as an authority on the topic and it's unlikely you can convince someone to make a purchase from you.