I have been promoting Clickbank links in both Twitter and Facebook but haven’t gained any purchase with even less-priced products. Do I miss something here? 
No. You just have to promote. I promote affiliate links via Twitter and Facebook and I have sales. Also huge clicks over 200.000 / month from those sites.
It sure is if you’ve got your strategy right. I personally know of colleagues who are doing well promoting their CPAs exclusively on social media. They spend very little time doing it btw 
just depends what you’re promoting and if you’re targeting the right people
There are so many ways promotion like Twitter, facebook, stumble upon , digg and mny more social sites or forums are available for the promotion
You have to be active on a regular basis in relevant facebook groups and sometimes post your affiliate link.
There must be a problem in the way you are marketing and putting up these on your social media accounts. You would have to sit back, reflect and then think of how to redo it to reap better benefits.
I am trying to do the same. In terms of the link, do I just put the link up there? or should I do something else about it? I mean, will people not purchase with the link if they know it’s an affiliate link?
There’s nothing wrong promoting your business in twitter and facebook. But all you need to do is to have more people to visit your link. Those people that who are interested to it.
Are you promoting them through your own personal Facebook and Twitter accounts?
This is a good discussion. I am also looking for answers. I am also starting an affiliate program but i don’t have much idea. Will be checking this thread.
Keep updating.
Thanks