I think it might be helpful to set a numerical cutoff and perhaps an editorial policy (EG so that terribly edited content or pure links don't hit the front page) and then stick to that policy. Before seeing what you did here, I briefly thought that this sort of action would be good for the recent vegetarianism discussion, simply because it had more than 20 upvotes and raised apparently legitimate issues about socially calibrating oneself on pragmatic moral issues that require abstract thinking.
Of course, that discussion implicitly criticized SIAI as visible non-vegetarians. The implicit potential danger of promoting this but not that is that this can be seen as consistent with promoting things that build SIAI and LW organizationally and thus clearly benefits yourself as the founder. Some readers might infer the existence of such a policy and think it is off mission relative to the "refining the fine art of human rationality" tagline.
The lack of one intervention can give lie to an explanation for an second intervention if the explanation would justify things that weren't done, like the way North Korea clearly had WMDs (and no oil reserves) but wasn't invaded, but the details of why it "didn't count" were never spelled out in plain english by policy makers, leaving people free to speculate.
Honestly, I think organizational development is instrumentally critical to the tagline mission, because institutions and F2F stuff can do a lot more a lot faster than mere blog posts, and there is all kinds of good literature to this effect. But these sorts of issues can be very tricky to get right if the inferential distance between the readership and the mods gets too large. The connection between institutional growth and front line effort isn't always obvious to everyone.
Having a bright line editorial policy that can be seen to promote content that doesn't obviously build the organization is probably useful for visibly signaling good faith from above. Another approach might be to directly explain part of the rational basis for pursuing certain kinds of institutional growth, so that instead of justifying this with "34 votes" you could have justified this with "34 votes and efficaciously pro-social".
(Also, on a general note, the front page is pretty awesome right now, with more solid content and less meetup stuff than has been normal for a while. If someone is doing something to consciously bring about this state of affairs, they deserve credit.)
Related: Purchase Fuzzies and Utilons Separately
We genuinely want to do good in the world; but also, we want to feel as if we're doing good, via heuristics that have been hammered into our brains over the course of our social evolution. The interaction between these impulses (in areas like scope insensitivity, refusal to quantify sacred values, etc.) can lead to massive diminution of charitable impact, and can also suck the fun out of the whole process. Even if it's much better to write a big check at the end of the year to the charity with the greatest expected impact than it is to take off work every Thursday afternoon and volunteer at the pet pound, it sure doesn't feel as rewarding. And of course, we're very good at finding excuses to stop doing costly things that don't feel rewarding, or at least to put them off.
But if there's one thing I've learned here, it's that lamenting our irrationality should wait until one's properly searched for a good hack. And I think I've found one.
Not just that, but I've tested it out for you already.
This summer, I had just gone through the usual experience of being asked for money for a nice but inefficient cause, turning them down, and feeling a bit bad about it. I made a mental note to donate some money to a more efficient cause, but worried that I'd forget about it; it's too much work to make a bunch of small donations over the year (plus, if done by credit card, the fees take a bigger cut that way) and there's no way I'd remember that day at the end of the year.
Unless, that is, I found some way to keep track of it.
So I made up several jars with the names of charities I found efficient (SIAI and VillageReach) and kept a bunch of poker chips near them. Starting then, whenever I felt like doing a good deed (and especially if I'd passed up an opportunity to do a less efficient one), I'd take a chip of an appropriate value and toss it in the jar of my choice. I have to say, this gave me much more in the way of warm fuzzies than if I'd just waited and made up a number at the end of the year.
And now I've added up and made my contributions: $1,370 to SIAI and $566 to VillageReach.
A couple of notes:
Let me know if you start trying this out, or if you have any suggested improvements on it. In any case, may your altruism be effective and full of fuzzies!
ADDED 12/26/13: I've continued to use this habit, and I still totally endorse it! A few addenda: