Should your web service have a free plan?

Lots of web services provide you with a free version of their service and a paid service. The idea is that customers are more likely to pay once they tried out the free version.

But if this is the case: Why is 37 signals trying to hide the free option? 

In this nice article why free plans don’t work a nice list of arguments that will stop you from automatically adding a free option to your service.

If that article has not convinced you yet: Try Instapaper free is taking an extended vacation