January 22nd Dong Nguyen was probably extremely excited about the couple months worth of revenue his marketing experiment had pulled off. With the recurring in-game ads and 800 reviews in a single day, Flappy Bird was beyond a success. Mission accomplished.
February 1st Dong Nguyen, on the other hand, must have questioned if the world had lost its mind.
On February 1st, reviews exploded to 800 in a single hour. 6,500 iTunes App Store reviews in a single day. February 1st is the day Dong Nguyen woke up, stretched, checked email, checked Twitter, checked iTunes, and witnessed millions of downloads happening.