Its down to two thing:
1) Your traffic method:
With traffic its generally down to things like ranking on search results (organic), social, video as well as ads. When starting out I prefer to use ads such as adwords for direct traffic and FB for list building... and in parallel implement SEO for the long haul.
2) Your unique proposition.
This is what sets you apart from your competition.. I recommend that you build a list before sending traffic to an affiliate site.. However there are times when that does not work... Either way once you present your offer (via email, landing page, blog etc) my technique is to offer free valuable bonuses on top of the affiliate product which you are promoting.... If you can also try locate the discount URLs if there are any with regards to the product which you are promoting - that way you really do provide an awesome incentive i.e. discount plus cool bonuses..