Affiliate networks are the middlemen for publishers and companies so that the former can find and join affiliate programs. CPA (cost per action) can be considered a subset of affiliate networking as affiliate networks can run these types of campaigns. There are, however, CPA networks, exclusive to CPA marketing.
A common use for it would be for running CPA campaigns for when a company wants to expand their customer base. When you pay somebody for driving traffic to your site, and getting people to sign up or offer up their information, that's CPA marketing.
If you're unsure of how and where to start, there's no need to fret. There are a lot of quality services offering this marketing technique. You will be guided through the process and given guidance throughout the planning of your own CPA campaign.
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