Well, for 5,000$ a month you can pull down 1,000,000 Twitter posts.  That's 33,000 posts a day , about 1/3 the daily posts nostr has now (according to nostr.band 80k).  So you pull these down, create keys for em, and setup some grouchy AI bots to reply sporadically to anyone that replies to the mirrored posts.

So, for 15,000$/mo you could double the amount of daily nostr posts with all kinds of content that would diversify the topics significantly.

Anyway, that's what other platforms do to bootstrap, they make fake content and/or pull it from an existing platform to seem like there's lots of users until the bootstrapping phase is complete.