Seems like very easy to abuse and harvest alts.
There's always been that one complaint of stakeholders: "I invited some people over but I didn't have the stake to curate them and no one bothered engaging with them so they didn't stick around". Of course things are very different now with communities, the @lovesniper initiative, our community incubation program and many other activities and projects outside of OCD that have made for far better user retention than in the past.
It's a phenomenal improvement, vastly different from before cOmMuNiTiEs and if user retention is far better than any other point before now, what was it like before? Engagement and traffic must have been completely dead seeing that user retention was so much worse.