Steve Smith observed that decades of online experience have shown consumer willingness to pay for "their passions." Dedicated fans of programs have long shown an interest in consuming more information and content related to the series.
"Crafting reasonably priced deep dives into these niches is one way that TV programmers can deal with the platform fragmentation currently challenging this old models. Apps may be one way of experimenting with a model that leverages fragmentation. It zeroes in on the niches that declare themselves when watching certain programs and then gives the network the opportunity to super-serve them in ways the niche gladly pays to access."Seems to be an idea worth pursuing.
Source - CBS Goes To The Paywall On '48 Hours Mystery' iPad App, Mobile Insider