Balancing Need and Want in the Product Development Process

I just read Matt Moore's most recent post over at Engineers without Fears.
I was inspired enough to comment as I felt his argument covered a key challenge of the Customer/Product Relationship.

As organisations which develop and Sell Products and Services, we need to sell to make ourselves relevant. In order to ensure we get and keep our customers we sometimes have to perhaps emphasise parts of the service which we know are going to appeal more to specific customer segments. That's called Marketing and PR, I think. The question is though, is that a form of prostitution, or just fulfilling a real need which actually exists?
As with most things, the challenge is to find the balance between creating a need, filling a need which exists. That's probably more sustainable than creating 'wants' in order to fulfill over zealous forecasts to keep the Shareholder happy.
(note: Image sourced from http://www.zazzle.com.au/)