And it's worth hundreds of dollars
Exactly one year ago, 19,000 people gathered at the Wenceslaus Square in Prague and demanded the resignation of Andrej Babiš, then Czechia's finance minister and now the prime minister without confidence, who had just been shown to have committed several immoral and illegal acts.
Babiš responded by saying that it was a ludicrously small group. After all, he had just posted a self-congratulatory text on Facebook (well, his PR guy Mr Marek Prchal did it for him because Babiš himself doesn't even know how to touch or caress a computer) and he obtained the same (?) number of 15,000 "likes" from his fans!
This response became one of the often quoted examples of his arrogance and detachment from reality. To "like" his text takes less than a second – a single click – while you have to reserve several hours (and maybe pay for the transportation etc.) to attend a rally. Only a lunatic or a hardcore demagogue could claim that these two expressions of sympathy are "equivalent" (Babiš is both, especially the latter).
Tetragraviton mentioned something similar, from the world of science. Nadav Drukker – whom I know rather well – was talking about a party where he explained the concept of citations to a non-science lady. He estimated that an average paper gets 50 citations (well, I would guess that it's already a better than average paper if it has reached 50) and the lady was stunned: Just fifty? I got much more for a LOLcat. Physicists must be losers.
Well, as Tetragraviton correctly says, her getting many more likes for a LOLcat than the number of citations of a physicist's paper doesn't prove that physicists are losers in comparison with the spammers who betray their friends' trust by spreading Internet banalities (thanks, Sheldon). The reason is that a citation is much harder – and requires more work and investment of one's good name – than a "like" on Facebook.
When a physicist writes a paper, he may have to reserve some 50-100 days for the work – although the research made for that paper isn't the only thing he's doing at that time. And the resulting paper may have some 50 spots for references to older papers in average (there are no quotas, however). It means that if you take my numbers seriously, one citation represents 1-2 days of the work by the author of the new paper! It's a lot. You surely spend much less time by a "like" – and you may easily "like" tens of thousands of posts or tweets a day.
The overall number of citations is the simplest one among the "good enough" criteria that may be used to rate the contribution by a scientist to the field of physics. The theoretical physics superstar Edward Witten has over 130,000 citations. Because he's been doing physics for decades, was getting a pretty good salary, some $3 million prizes on top of that, plus other things, it may be OK to estimate that he has earned $13 million. I am sure that some people have a better idea but an order-of-magnitude estimate is OK.
That's $13 million for 130,000 citations – about $100 per citation. In fact, by this ratio, Witten's labor belongs among the cheapest ones. His cost of a single citation may be lower than the cost of a citation among some good people in India – and believe me, Indians have an amazing production of science per dollar that is invested into them.
In fact, if a billionaire searches for some people who might be encouraged to do more impressive research for an extra buck, some underfunded and relatively unknown person somewhere, he may very well end up with Edward Witten after some research of the market conditions. ;-) I think that for more typical people, the cost of a single citation is several hundred dollars, not $100. I invite the people paid for physics research to calculate their ratio – and if they end up with more than $1,000 per citation, they should be silently ashamed.
So a citation is worth hundreds of dollars, and is equivalent to 1-2 days of the work by a theoretical physicist. It's no coincidence that the salary for 1-2 days ends up being several hundred dollars, too. You really shouldn't compare it to a "like" on Facebook or Twitter. It's harder to meaningfully cite someone – because you actually use his work, and you use the things from a previous paper while writing a new paper during 1-2 days in average. Also, the citation to an older paper means that the new author sort of claims that he takes the responsibility for claiming that the older paper isn't some completely wrong or worthless garbage. And no one wants to have regular papers with more than "hundreds" of references in them because it looks stupid – or it looks like an effort to befriend or bribe too many people.
On the other hand, "likes" on Facebook – like those under the posts signed by Babiš (who didn't write them) – may be automatized. A computer program may add "likes" to many places. A random bunch of 1.5 million brain-dead Internet users (I picked Babiš's voters to have a specific example in mind) may mindlessly click at "like" whenever Babiš's computer and P.R. guru Mr Prchal writes anything, too. So such "likes" are basically worthless most of the time – much like a typical e-mail message that ends in your spam folder.
The lady who was shocked by Nadav's information about the number of citations as well as Andrej Babiš represent remarkably unreasonable people who are ready to identify things that can't be considered equivalent by any stretch of imagination. But some people may simply "like" equality – including the equivalence of things that are completely incomparable. These people are basically incapable – or pretend to be incapable – of distinguishing gold and šit. Well, this fact has a simple reason in the case of Babiš: he earned his first gold (his first billions of crowns) by trading šit – I mean it literally – and as a politician, he has based his success on collecting šit on the street – here I am metaphorically talking about his voter base that is being bought by the cheapest slogans you may imagine.
But there are lots of other people like Drukker's female companion at the party who just don't have any respect towards science or anything that is hard – and who will always tell you that these difficult things that depend on lots of talent, hard work, expertise, integrity, and patience are equivalent to their generic šit that is "also" measured in some units.