Personally, I’d define spam as widely distributed advertisements without consideration to the audience that is receiving it. You just get it because you are on whatever mailing list that was bought or compiled. In general, I would not consider a targetted ad to be spam, unless their targetting is bad enough that it’s virtually indistinguishible from spam, because I may have interest in seeing it.
Specifically to the OP, I think twitter and facebook are fundamentally different in how they handle these things. I don’t do twitter, but I am under the impression that in general you see all the tweets from everyone you follow, no? The point of the veritasium video (which is an excellent channel, by the way) was that with facebook, you are pretty much guaranteed not to see everything that anyone posts.
The way facebook works is it “tests” out posts with a percentage of friends/likes/follows and, based upon the interaction that it gets, you shows it to a larger audience. Thus, if you have, say 1000 likes, but typically 50-60% of them will intereact with a post, then if they test a post to 5-10% of them, chances are enough will interact that it will spread to all 1000 likes. If, however, you have 1000 legitimate likes and 9000 fake likes, your interaction rate will drop to about 1/10, and now that test audience is diluted so it is far less likely to get seen by all the legitimate likes. So, there’s an irony there that though, the latter seems to be more popular, and thus should spread faster, it has the opposite effect.
There was a similar video on comparing how youtube and facebook work either from the same channel or another one in that circle of channels and how it’s interesting that youtube and facebook are somewhat similar, in content creators posting content and wanting people to see it, but they have almost opposite business models for it. In youtube, the content provide gets paid based on views, and the more views they get, the more promotion they get, showing up in searches and all, which means the promotion is generally more targetted. Where in facebook, the content provider has to pay to get promoted, and the promotion pretty much just makes it show up in suggestions, so it’s much more like spam than targetted, which is why the results were so terrible.
So, then, how does twitter work as far as what tweets you do and don’t see? Do you only see some tweets from the people you follow? Maybe paying to promote it guarantees that all your followers will see that tweet? Does it go farther and show those tweets perhaps to followers of followers? I think if it’s at all like the facebook model, it’s almost certainly a waste of money, but if it’s closer to the youtube model, where the promotion is more likely to go to people who may be interested, then it might be worth the cost.