When you are promoting affiliate products you must never reflect in your sales letter that it is not your own product. Sell affiliate products like you own it. Optimise your site for search engine and try to get high quality backlinks from do follow websites which will help to increase PR of your website. With high PR, you will be ranked well in search engines and you will get more organic traffic (which is best of all traffic).
For my first website I made first sale after nearly 6 months, so you need lots of patience. Good luck.