The pinnosphere is the aggregate of all the images that have been uploaded by users on copyright-infringement platforms such as Pinterest.
Potential website visitors have a finite amount of time available for exploring the internet; viewership is therefore a finite resource that webmasters compete for. They compete for this commodity (visitor traffic) in order to display advertisement, or make sales of products. The larger the size of the web, the smaller the amount of time spent per website, on average.
Copyright-infringement platforms increase the size of the web by multiplying the number of pages where content can be viewed, even if this content is often repeated (multiple original pins from source, pins from search engine result pages, repins, repins of repins). In the aggregate, this swelling of content reduces the amount of time people spend on the source websites.
When website visitors spend more of their finite internet viewing time on Pinterest, they spend less time on the source websites as well.
Further, the source websites have to compete with their own infringed images in the pinnosphere (some creators may have more images in the pinnosphere than on their own websites) - with the added attraction of everyone else's best work, and the users getting their egos flattered with comments and followers for their great "picks" while the originators themselves lose both traffic and feedback.
There are reports of Pinterest links driving very little traffic to the source websites.
In her blog post, No Interest in Pinterest, Annie Paxye writes: "I’ve been told by people that I should be flattered that my images are ‘pinned’ or that I should be grateful that it brings traffic to my blog. But after seeing the flow and traffic over time, it just feels like stealing and the traffic seems to have no value. I’m not connecting with more people through this traffic and I’m not hearing why someone likes my posts or images."
Similarly, Bailey of the Mustard Ampersand Blog writes: "While I do get marginal traffic from Pinterest (and by marginal I mean less than 50 total referrals over a month, far fewer than my other networks), it’s not proportionate to the amount of views, repins, likes, etc., that I get on Pinterest. I don’t expect every user to click through. But Etsy has a strong stats program in place, and I can see exactly how many of my referrals are from Pinterest – and it’s not many. Compared to how many referrals I get from Facebook and Tumblr, it’s shockingly low."
Copyright-infringement platform users often have very limited understanding of the workings of the internet and operate under the delusion that the only way images can be monetized is with the old-fashioned photography business model of licensing for printed applications or other commercial broadcast. They may believe that because they wouldn't "buy" licensing to the images they upload on the servers of copyright-infringement platforms no matter what, they are not hurting the originators of the work. They are not cognizant that on the internet, images are often worth much more than the object they represent, and that the image itself has become the commodity that is consumed - a commodity that is often monetized with advertising.