Affiliate marketing is really exciting. Its promising but at the same time requires a lot of efforts. It can be seen ass "Give And Take" policy.
The more you give the more you will get.
The best people to contact are the people who are able to engage more audience you trying to target. Below are some ideas:
These are the people who write lot and lot of bogs. And there are people who read their content and are waiting to hear what bloggers have to say.
You can easily find them by searching the popular article in your niche and contact them and offer them to write their next blog post including a backlink to your website.
There are people who write reviews about various products and companies. You can get hold of one and ask them to write a review about you on their website.
They are the best way to reach the mass of people. You can look for the YouTuber whose videos are viewed by your target audience. And ask them to make a video about your product.
Social Media Celebrity:
You can look for the social media account (Twitter, Facebook, Linkedin, Medium, or even Quora) with many followers. That's it once you find your ideal account. You can contact him/her to share a link to blog post on your product or service.
These some of the simple ways to do affiliate marketing.