Facebook Affiliate Troubleshoot

Hi All,

So I have for past 3 years on and off built a Facebook page promoting discounts and offers for products using then associated affiliate links to make sales and such. I have a page which has 27,000 active likes 99% of them being women and over 80% between age 25 and 45.

I've tried to focus on this demographic and post links with offers etc that might interest this audience (e.g. clothing, beauty products). Posts vary from 40 reached to 2000 reached, But have very little conversions, despite Facebook insights saying more than 20k of users are active everyday so posts don't compete with other posts during the day.

Any ideas what could be the bottle neck here?

For reference, page is UK Discount Codes, websites I affiliate link are through affiliate window and generally all well known clothing retailers etc.

Any help would be appreciated.