And yet almost everyone I know in tech knows about it, even my non-tech friends that use mastodon and pleroma have heard jokes about it. So given the exposure it's got them, it was pretty good for marketing.
I could be wrong on that, but my personal anecdata is that noone who doesn't already care about free software is really aware of their message about free software.
Some anecdata: My ex, whose parent is interested in computers but she herself does not have much of an interest and only barely knows what Linux is, joined mastodon before me, and the majority of her three hundred-odd follows do not know what Linux is.
Most cishet groups don't have a clue about mastodon or won't budge from facebook because they don't have a reason. The blatantly fascist-supporting twitter moderators, and the hostility of facebook's real name policy has given that incentive to queer people.