Publons - is it a serious thing? Recently several different, unrelated publishers suggested on their websites to join Publons, which is meant to acknowledge referees for peer-reviewing submitted manuscripts.

Publons even suggests to forward them emails to add all your past review work:


  We've set up a process to make populating your review record as easy as possible:
  Search your inbox for "thank you review manuscript"
  Forward those emails to reviews@publons.com
  We'll verify and add your reviews to your profile (without showing their content or the title of the manuscripts)


This all sounds very iffy and hence my questions: 


Given their suggestion to forward [confidential] emailexchanges between journal and reviewer, is Publons a scientifically ethically sound initiative?
Not a hoax?
If it's ethically OK and not a hoax, what will it yield scientists in the long run, other than a  verified referee record? Isn't reviewing expected from every researcher?


Related question on academia SE: Is it worth creating a profile with Publons?
Here is their current web page, which in contrast to the Google+ page you linked to appears to be up-to-date.
Although this is the first time I've seen this site, my impression is that it's ethically okay and not a hoax. That said, it also seems quite unnecessary to me, and I would not bother to use it.

What will it yield scientists in the long run?

--  I would estimate:

With about 2% probability, the website will catch on and become popular. Probably this would be at the insistence of university administrators, who are often looking for new ways to measure and evaluate the performance of faculty.
The website will yield another hoop for researchers to jump through, and possibly (as the website claims) to increased recognition of researchers who do an unusually good job of peer review.

With about 98% probability, the website will largely be ignored, and the net effect on the scientific community will be nil.


In general, I would advocate ignoring advice originating from commercial publishers; personally, I would only consider using this site  if I were urged to do so by scientists in my field or by administrators at my university.