Private Eye on "Fake News" pic.twitter.com/TyFHvN6npB— Tom Kilroy (@kilroyt) November 26, 2016
I'm not sure exactly how many tweets/retweets you have to get for it to be classed as "going viral" but the phrase was used by The Poke.
It can increase followers quite a bit though, which can mean more work in the long term. However, that can only happen if you credit the cartoonist when sharing work online, and, if possible, include their Twitter name (or Facebook page, web link, whatever is appropriate).
The Poke post, above, did not do so originally but they redressed the balance when I asked them to in a tweet. Tom Kilroy who posted the version that got the most retweets did likewise.
I balk at approving of websites that make money from adverts using such shared cartoons as free clickbait content, but generally I try to see online sharing, by individuals at least, as a positive thing.
other cartoons such as "Votey McVoteface" have been shared a lot online) it's nice to know that a cartoon has struck a chord. But please, don't forget to credit the cartoonist.