Email marketing: This is best in small doses. You don't want any partners sending out bulk emails to customers who aren't interested in your products or services, but with proper consideration for who's receiving the email, this could be an effective method. For instance, if you sell design tools, you might reach out to marketing agencies and ask, if they're working with a specific client on a design project, whether they might consider sending a URL from your site within the body of the email. This could help their clients leverage your tools to create higher-quality content, while giving agencies an added source of income.
The products and services you will be promoting to your audience must be relevant and good quality. Make sure you believe in them and know everything about them, because this will be crucial to you delivering the sales pitch to your audience. You need to build trust with your audience so make sure the products and services you choose to promote are trustworthy enough.
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.