Persuasive marketing with reciprocity

The principle of Reciprocity is that when you give something to someone, they not only give you something in return, they want to.

I've noticed a trend on the web where more and more companies are requiring that you give them your email in order to read their case studies or blog posts about a particular topic.  Other companies are charging a "tweet" for the article, sight unseen, as payment.

This is not a great use of reciprocity.  When websites require the exchange upfront, the reciprocation is on their part.  For your email or tweet, they will share their knowledge with you.

If you have a website, consider the consequences.  This doesn't promote loyal followers that will spread your message.  This creates individuals who feel that you owe them for their payment.  The job of exciting them and exceeding their expectations has just gotten exponentially harder.

If you give useful information to your visitors, they will feel a sort of debt to you.  The more useful the information, the more likely they are to return and feel the need to reciprocate.  If you want a tweet or their email address, all you have to do is ask.  The beauty of reciprocity is that you can build up credit and ask for something big when it counts.