Social media is increasingly the internet: Facebook was founded in 2004, and it ate the web as we knew it then — a collection of microsites and curiosities run by so many individual proprietors, individually. It used to be that personalization was what you did to your site; now it’s found in the ads you’re served. Peach — the microblogging platform— was seemingly designed against those circumscribed possibilities, as an antidote to the weird world-eating dominion of the...