If $4700 in ads could sway an entire US Presidential election, that has to be the most cost-effective use of money to achieve a foreign policy objective in the history of the world.
The problem with Correct the Record was, other than an extremely shortsighted objective, the fact that everyone knew about it. People who legitimately defended Hillary Clinton were assumed to be shills, to be "correcting the record" and this backfired tremendously.
Keep that in mind with these releases. The advertising dollars aren't the major news. It's the sock puppets and vote/conversation manipulation that are by far the largest component of the disinformation campaign. Those costs won't be public, either.
That's a little disingenuous. IIRC, Facebook identified at least a $100k more on its platform, and they permitted finer-grained targeting than Google.
You're right that it's hard to believe stuff like this tipped the election outcome, but it's not impossible that it did. The sales pitch of targeted online ads is that they're cheaper and more effective than mass-market ads. Also, given the way US elections are conducted, the right pressure applied in the right areas could deliver an outsized effect on the outcome. Taken together the amount of money needed to sway a close election could possibility be less than one would expect.
True. But presumably the experienced veterans on Clinton's team also knew about it. It's not exactly a secret how US elections work, at least it shouldn't be the people trying to be elected.
$1B+ budget would have been enough to blanket all the right areas with ads day and night and even have money left over for people to walk door to door and ring doorbells.