> From an academic perspective it is worth exactly as much as a blog.

From the perspective of peer review, yes. But per google scholar that paper has been 66 cited times, including in many articles that are in at least somewhat reputable journals (published via Elsevier, ieee, Springer, etc) and apparently two books [0]. So I think it's pretty clear that being a "scientific paper from Princeton" was significant reputation wise regardless of whether or not it was peer reviewed.

[0] https://scholar.google.com/scholar?q=Epidemiological%20model...

I was also skeptical about the citations so I checked that two with freely available pdfs were actually this paper, they were

[1] https://pdfs.semanticscholar.org/4ebb/b654c59aff454ad97301e6...

[2] https://arxiv.org/pdf/1509.07805.pdf

Right, but it's not a scientific paper. It's a problem when people trust something just because it came out of Princeton, but the problem you're identifying isn't one with scientific papers (and the citations you've identified are places where they're using the Cannarella paper as an example of people being interested in applying epidemiology to social networks, not citing the research they did as accurate or important.)

The majority of the papers citing it that I checked (including the two you have linked yourself) makes the citation for the idea of the method (using epidemiology models in the context of social media), not for the results.

several of my blog posts have had high google scholar citation counts; doesn't make them scientific articles, though. still just my personal opinions.