I think it's going to be a lot of money spent on something that'll have minimal impact on actual distribution and perhaps end up causing ill-will like the various *AA file-sharing lawsuits over the years or the old Napster/Metallica situation if they get too sloppily enthusiastic with the takedown notices.
People have grown to really hate the use of the DMCA as a pre-emptive scare/strike tactic because it's been abused over the years for some inanely nonsensical stuff where the supposed rights-holder was throwing around their weight to suppress fair use stuff*.
Also, those listings will grow back like mushrooms in your front yard. Take a few down, in a couple of weeks more will sprout, and unless they start to engage in those sloppily enthusiastic tactics where they send down automatic takedowns to everything which mentions their names/book titles, then the authors will have go back and manually check another batch of links/send permission for the notices again and again in a never-ending battle.
It seems more of a feel-good band-aid thing for the publisher/authors.
But if it really does make them feel better and they think it's worth spending the money on, then I suppose there are worse things they could be spending the money on (though I'd personally put that $15 per author per month into growing the company or paying out a higher author royalty to attract more authors or something).
*
Vide the current
MightyGodKing comics blog, which IIRC had its origins in a takedown notice over an Archie parody creation/discussion community over at LiveJournal which the Archie people complained about with the pre-emptive DMCA strike option.
This led to MGK, who was simply the moderator for the group, having his personal LiveJournal and other unrelated moderated communities suspended as well as being banned from LJ for no better reason than that the Archie people didn't like fair use parodies of their work.