Note that this paper is from Nature: Scientific Reports, which is also published by Nature Publishing Group, but is not the Nature journal you're thinking of. SRep is not in the same tier as Nature.
I'm guessing that it's still a long way removed from "spam", though, right? :-)
Edit:
See here for one particular discussion, from last year
http://blogs.sciencemag.org/pipeline/archives/2016/06/15/mor...