Good question!
As you rightly suspect, one of their strongly professed goals is the "viral" aspect, i.e. "we have been given a mission to spread the wonderful/enlightening message from the benevolent aliens that suspiciously look like a bunch of French dudes in jumpsuits".
Besides that, they care a lot about:
This may sound funny, but yes, they think of themselves as supporters of "science" and "scientific" views (versus religion). And in their cheering/repeating phrases heard from the scientific crowd, they even got a few things right, especially those that were well established at the time when their "message" book was written.
They consistently put emotional effort into thinking about this, but I do not know of any instances when they achieved an outcome in the world.
This one seems to be a pretty real positive effect, especially in the context of Japan, with its overly rigid social rules that cause a lot of anxiety and unhappiness all around.
While their epistemology is abhorrent, the methods they use for this are pretty efficient, and this aspect provides clear value to members.
I personally use "take a deep breath and feel grateful" as a primitive action, which is perfectly compatible with rationality, and has measurable effect on quality of life (especially in case of countering SNS responses). Most cults and religions know that it works, and use it in a "package deal" with brainwashing. But regardless of how often they are misused, techniques like this are valuable, and so is spreading their practice in communities.
Note: I kind of sound like I'm defending them, but please keep in mind that I only take this stance because it's opposed to the default LW reaction, and therefore more likely to produce non-tautological conversations.
I was invited by a stranger I met on a plane and actually went to a meeting of Raëlians (known in some LW circles as "the flying saucer cult") in 沖縄, Japan. It was right next to Claude Vorilhon's home, and he came himself for the "ceremony" (?) dressed in a theatrical space-y white uniform, complete with a Jewish-style white cap on his head. When saying his "sermon" (?) he spoke in English and his words were translated into Japanese for the benefit of those who didn't understand. And yes, it's true he talked with me briefly and then hugged me (I understand he does this with all newcomers, and it felt 100% fake to me). I then went on to eat lunch in an 居酒屋 with a group of around 15 members, who were all really friendly and pleasant people. I was actually treated to lunch by them, and afterwards someone gave me a ~20 minute ride to the town I wanted to be in, despite knowing they won't see me ever again.
If you have ever wondered how it is possible that a flying saucer cult has more members than EA, now it's time to learn something.
Note: I hope it's clear that I do not endorse creating cults, nor do I proclaim the EA community's inferiority. It hasn't even crossed my mind when I wrote the above line that any LW'er would take it as a stab they need to defend against. I'm merely pointing to the fact that we can learn from anything, whether it's good or bad, and encouraging a fresh discussion on this after I gathered some new data.
Let's do this as a Q&A session (I'm at work now so I can't write a long post).
Please ask questions in comments.