The article says "80% of its peak user base within the next three years", but the title says "by 2017"? Also, I'd have liked to know to what Facebook would los

The article says "80% of its peak user base within the next three years", but the title says "by 2017"? Also, I'd have liked to know to what Facebook would lose its users. During the Pokémon GO craze Facebook and other social sites lost temporally their users before they came back.