I'm not sure it's "not interested", more not being accustomed to the platform and what is available.
Facebook advertising is still remarkably cheap and effective if you know what you're doing.
Amazon emails to me are generally highly targetted in that they email me with products I've looked at but not bought.
Facebook don't decide what to advertise you, advertisers decide what to advertise to you. They can be as specific as they like, or not. A restaurant, for example, will almost...
This tool is very handy at:
a) Viewing past price changes on a product at Amazon.
b) Setting up price alerts (eg if the price of X falls below £Y then please tell me)
http://uk.camelcamelcamel.com
(If you use it, please then come back to NSC to click through to Amazon if you can!)