CPA works well with both free organic traffic and paid traffic. Free traffic takes time and money to build up, but results are decent in the long term. You need to be careful about what traffic sources are allowed, and which ones are not allowed by the CPA networks. Most networks are wary of the common free traffic sources, unless you have an established blog or YouTube channel.
Paid traffic provides instantaneous traffic but you will need to spend a lot of money to become familiar with what works and what doesn't. Most of the paid traffic sources have a high minimum deposit amount like $200 or $500. Running paid traffic has no guarantees though, and you need to study and prepare well before you start your campaigns. Almost everyone incurs losses in the beginning, learns form mistakes and then creates more campaigns. Be ready with $500 to $1000 at least.
It is a bit tough to get accepted by CPA networks also. There are various techniques to seek approval correctly, mainly by showing your credibility and convincing them that you are not going to spam anywhere.
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