I think this is being complicated unnecessarily: the original stock libraries functioned perfectly well before digital,
But the music industry functioned perfectly well before iTunes also. At least from their perspective. Clearly things have changed since then, both in technology as well as in society, specifically the consumer within that society. And how we consume music is very similar to how we now consume images. But also other pieces of information like news, and video etc… It all inevitably comes down to the fundamental law of information:
The quality of information is inversely proportional to its quantity and speed.
So, the added value of an agency is not (anymore) in the gathering of images (or photographers) but very much in the automation of that process, and/or in the filtering/redaction of the results. i.e. a photographer would select library X because they make the process of supplying and leasing images very simple, easy, and worry free. Or an agency would select some library because they ensure a specific type of photographers or genre of images, where you are certain that the results conform to some standard, etc…
You gather your news from many sources, but for certainty you will usually select a few sources that you regard as quality sources. And the quality is a result of the filter/redaction applied at that source. Thus getting back to the fundamental law: filtering information = less information = more quality = added value
Oh yeah, and whether that added value is taxable in any reasonable way remains to be seen. But I certainly like some of the comments I read accompanying this article
, specifically how moving around money in microtime doesn't specifically represent productivity of any sort...