Anyone know their methodology? I clicked around a bit and couldn't find any information. Without knowing more my prior would attribute it to a bug.
The article clearly discloses the inherent issues at play.
> Going forward, we’ll be watching closely to see what longer-term trends emerge. Bugs in the Facebook advertising tool that we draw this information from, seasonal changes like college graduations, and other short-term factors, can influence numbers month to month and obscure what’s really happening.
I could see people getting bored / busy and not bothering to use it any more, but it's unbelievable that 1.5 million would delete their accounts in one month.