Unusual things attract crowds. Big events, celebrations, ceremonies, police arrests, traffic accidents. Big, unusual, things nearly always attract a crowd.
Marketers are fantastic at getting crowds. They do something big, promote it, and a crowd gathers. It doesn't matter if it's online or offline, unusual things will attract a crowd.
The problem with crowds is they’re temporary. Sure, they can be big, but they dissipate once the event/activity/whatever brought them together is over. They don't form bonds with others that encourages them to return.
Don’t ever mistake a big crowd with a community. The skill of weaving relationships between people is the opposite of attracting a big crowd. Relationships take time to develop and can last forever. Your crowd will be gone very soon.
Marketers attract crowds, community builders weave relationships.
Which do you want to do?