I was tempted to add posting good or even good and original content as a requirement, but such a requirement is not honest.
What you should care about is the duration of time between the comment/thread time of issuance, and the time when it gets either self upvoted with an effective SP > 1/2 of your own maximal SP, and for this matter, by self upvote I do include vote bidding.
If you are not given enough time to stand a chance of receiving fair curation rewards, which are =< 1/3 the author's reward anyway, you should feel content to let the author care for his reward, since it will be at least close to what your upvote would have given him, unless you are an orca or more voting at full force.
Self voting (including vote bidding, circle jerks, etc and vote guilds) increase the profitability of upvoting the content only as long as they happen after a period long enough to allow curation to be profitable, which under current (2017 November) terms, self vote should be at least over 24 hours since publish time.
This is the main reason why I stopped upvoting most of the good content I see here.
The publishers I stopped upvoting clearly do well without me, and if I upvote them, I will hurt myself more than benefit them, in ratio terms.
To me it is more economical to let some of my voting quota go to waste, than to try to maximize it, and this can be a thread on its own.