Last year, Google changed its algorithm to favour mobile-friendly sites.
The change was dubbed Mobilegeddon as it threatened businesses that had not built mobile-friendly sites with lower rankings.
Now, Google rival Facebook is weighing in on mobile-friendliness. Citing research, the social network says up to 40% percent of users will abandon a mobile site after three seconds of delay.
That, for obvious reasons, is problematic for advertisers with slow-loading mobile sites who are paying Facebook for clicks.
17 great parallax scrolling websites