How big are the "megajournals" compared to arXiv?
I use data from the article
 Have the “mega-journals” reached the limits to growth? by Bo-Christer Björk https://dx.doi.org/10.7717/peerj.981
, table 3
and the arXiv monthly submission rates
To have a clear comparison I shall look at the window 2010-2014.
Before showing the numbers, there are some things to add.1.
I saw the article  via the post by +Mike Taylor
 Have we reached Peak Megajournal? http://svpow.com/2015/05/29/have-we-reached-peak-megajournal/
I invite you to read it, it is interesting as usual.2.
Usually, the activity of counting articles is that dumb thing which is used by managers to hide behind, in order to not be accountable for their decisions.
Counting articles is a very lossy compression technique, which associates to an article a very small number of bits.
I indulged into this activity because of the discussions from the G+ post
and its clone
[4'] Eisen’ “parasitic green OA” is the apt name for Harnad’ flawed definition of green OA, but all that is old timers disputes, the future is here and different than both green and gold OA https://chorasimilarity.wordpress.com/2015/05/28/eisen-parasitic-green-oa-is-the-apt-name-for-harnad-flawed-definition-of-green-oa-but-all-that-is-old-timers-disputes-the-future-is-here-and-different-than-both-green-and-gold-oa/
These discussions made me realize that the arXiv model is carefully edited out from reality by the creators and core supporters of green OA and gold OA
I invite you to go and read all, but I cite two revealing comments:
(a) +Michael B. Eisen
, comment in  (I don't know how to give the link to the comment, you'll have to use the link to the post) which replies to this part of one of my comments:
[me] " I am not arguing with your other writings, but this title looked to me misleading. From the post I learned about stuff which puzzled me in the past, for example why the non-symmetric definition of green vs gold OA from wikipedia: "The two ways authors can provide open access are (1) by self-archiving their journal articles in an open access repository, also known as 'green' open access, or (2) by publishing in an open access journal, known as 'gold' open access." https://en.wikipedia.org/wiki/Open_access
[Michael Eisen, my boldface] "There's a confusion of terminology here. Although the terms are not used consistently, in most usage "green open access" refers specifically to the practice of publishing a paper in a subscription journal and then making the paper freely available in an archive. Thus placing preprints in arXiv prior to publication is not green OA - it is something else
. Indeed the origins of "green" in "green OA" refer to the green light given by publishers to allow versions of their articles to be posted. For example, Harnard - undoubtedly the biggest proponent of green OA - makes it clear that the subject of his efforts is articles that appear in peer-reviewed journals. Hence my usage of the term green OA to apply specifically to the subset of efforts to make works freely available that employs the "parasitic" model - I was in no way criticizing arXiv - which is doing things the way they should be done. "
(b) +Stevan Harnad
, comment https://chorasimilarity.wordpress.com/2015/05/28/eisen-parasitic-green-oa-is-the-apt-name-for-harnad-flawed-definition-of-green-oa-but-all-that-is-old-timers-disputes-the-future-is-here-and-different-than-both-green-and-gold-oa/#comment-11025
at the post [4']
[my boldface] "Virtually all arxiv deposits are submitted to and eventually published in refereed journals, Both the pre-refereeing preprint and the refereed postprint are shared on Arxiv. Arxiv is simply an access-provider, just as an institutional repository (IR) is. The only difference between an IR and Arxiv is that the IR is hosted by the author’s institution and Arxiv is hosted by Cornell. Otherwise they are absolutely identical, for both preprints and postprints. Same is true for deposits on authors’ personal websites
Both (a) and (b) are very far from reality, because arXiv is not only a repository where people put things which are either pre*print* or post*print*, but something more: a model of scientific communication which works because we need it, which does not need publishers to function.
ArXiv say in their whitepaper: http://arxiv.org/help/support/whitepaper
"The e-print repository has transformed the scholarly communication infrastructure
of multiple fields of physics and plays an increasingly prominent role in a unified set of global resources for physics, mathematics, computer science, and related disciplines. It is very firmly embedded in the research workflows of these subject domains and has changed the way in which material is shared, making science more democratic and allowing for the rapid dissemination of scientific findings
. [...] Most scientists and researchers who post content on arXiv also submit their work for publication in traditional peer-reviewed journals. However, famously reclusive Russian mathematician Grigori Perelman's 2003 decision to post his proof of the 100-year-old Poincaré Conjecture solely in arXiv underscores the repository's importance and its role in transforming scholarly communication."Now, let's see those numbers. Just how big is that arXiv thing compared to "megajournals"?
From  the total number of articles per year for "megajournals" is
(for 2015 the number represents "the articles published in the first quarter of the year multiplied by four" )
ArXiv: (based on counting the monthly submissions listed in )
2015: 100,628 (by the same procedure as in )
This shows that arXiv is 3 times bigger than all the megajournals at once
, despite that:
- it is not a publisher
- does not ask for APC
- it covers fields far less attractive and prolific than the megajournals.
And that is because:
- arxiv answers to a real demand from researchers, to communicate fast and reliable their work to their fellows, in a way which respects their authorship
- also a reaction of support for what most of them think is "green OA", namely to put their work there where is away from the publishers locks.