I was browsing the AppStore the other day and I saw that Instapaper was cheaper than its normal price
Maybe if this were the original price I would have gone for Instapaper over ReadItLater ;-). In any case, I was in a temptation to buy it!  After all, Instapaper was my original "save for later reading" application on iOS, and I only changed to ReaditLater (now Pocket) because there was no free version on the iPad, whereas there was a free version of pocket, and pocket had a smaller price tag for the premium features.

Now the field has changed a bit.  Pocket has become free. Spool has emerged as another competitor, and of course there is also readability. All of these options are free.  Which makes me wonder, is there a spot for a paid app, like Instapaper, in this field?  What would you say to someone who was interested in getting a "read this later" app for their smartphone or tablet? How would you convince them to go with the paid Instapaper, versus the free Pocket, Readability and Spool?