Instagram announced Wednesday that it has amassed 700 million monthly active users (MAU) since launching in 2010, a more than 16% increase in just four months, and a 40% increase in one year.

Why it matters: Instagram announced the growth achievement the same day Twitter reported its Q1 earnings, where it touted a 2.8% quarterly increase in monthly active users to to 328 million — still less than half of the user base of Instagram, which is four years younger. Instagram rival Snapchat will also be taking note of these numbers, as its audience has dwindled since Instagram launched a copycat stories feature in August. Instagram's stories audience has increased so quickly that it surpassed Snapchat's total audience by nearly 40 million MAU a few weeks ago.