You can find the most popular CPA networks in this page. What is CPA? CPA is Cost per Acquisition or Cost per Action (CPA) a marketing metric that measures the cumulative costs of a customer taking an action that leads to a conversion. There are a lot of CPA networks on internet and you can choose any of them as a tool of affiliate marketing.
As Levelnaut website is mostly oriented to the topics of crypto, education and marketing, this list is focused on them too.
Some more useful links