I don't know the exact amount. I remember it being described as a small vote on a small account. Whatever the number, I know it is significant because until the latest hard fork, people with small accounts did encounter the situation where they weren't permitted to vote because the deduction took the vote to zero (which was changed in the fork, unfortunately being part of the new conditions which led to one of the chain-crashing bugs).

EDIT: I looked this up, it is 50 million rshares, not 50 rshares. It corresponds to an account with about 1 SP making the typical 10 votes per day, an account with about 10 SP making 100 votes per day, etc. Massive splitting down to, say, 0.1% votes by a moderate stake account will destroy the vote power, and if you see someone/bot doing that it indicates not a successful strategy but likely a mistake.

It doesn't work with the smallest upvotes given but when the vote value is between something like $0.01 and $0.001 it can work.

"Is there a store of empty accounts somewhere someone is willing to sell in bulk at a large discount?"

Funny you should mention that because I have seen a literal web store where these were being sold. I don't know if this still exists, but someone wanting to milk the system can surely find a source of such accounts by asking around. I occasionally get solicited to buy them, although (note to would be solicitors:) I don't have any interest.

I have more account tickets claimed than I have use for. Hmm..

There is in fact, currently, limited demand for this specifically because the system is designed to avoid introducing incentives for splitting (although there are still some), and when developers do find such incentives they try to come up with ways to remove them rather than adding more.

This is a good point. Someone else already pointed that out and I'm perfectly aware that multiple accounts is an obvious solution in many other contexts. Oh well, at least this post sparked a discussion.

"You should take a look at the user @eforucom"

Looking at one particular account often doesn't mean much. The curation return may appear high because of consistently trailing votes,

It's obviously a case of successfully following larger voters.

but in fact that return is being shifted from the trailers to the leaders.

Anything to back that up with?

This may or may not apply in this case but I'm always skeptical about claims about a particular account which don't make a more comprehensive analysis. "While his curation rewards haven't been anything to write home about very recently" I'm really not sure what to make of this. Very recently may be random variation, temporary conditions due to the fork, changing competition, etc. Without a better analysis, there is no there there.

What I suspect is that HF21 has caused the author rewards of the authors he's been following to change.

"issues raised here is not "mostly wrong""

Your post is mostly wrong in part not only because it is unlikely (or at least not well supported) that anything harmful exists,

Content-agnostic voting is harmful.

but because the suggested "fix" introduces account-splitting incentives which is contrary to an important Steem design principle.

As account splitting always remains a possibility and that because, as you say, there is an efficient market for alts to be bought and sold in bulk, anything account splitting is a good response to won't work.

If that really is an "important design principle", then that's a design flaw as there is no way to keep anyone from creating multiple accounts like on Voice that has a system in place that stores a unique hash of personal identification information. (Just to be clear, I'm not in favour of that or anything like that being implemented on Steem.)

If you: a) have better support for the idea that there is a problem worth solving other than the observation of some votes existing which are likely automated and have a nonzero return (this is fully expected and by design),

"Some votes existing which are likely automated and have a non-zero return"

To call that an understatement is an understatement. @eforucom has upvoted nearly 200,000 times since the account was created in August 2016. My account was created about six months later and has voted about 26,000 times. And I have been autovoting at least for a year. The entire premise of PoB relies on most people voting thoughtfully.

and b) have a proposed solution that doesn't introduce/increase incentives for account splitting then you may be on to something. But right now, you aren't.

Splitting as a response is indeed successful against any tweaking of voting percentage curves. That is why the only solution can be gently nudging those users who have a reputation to lose towards voting more responsibly.