As cartoonist Scott McCloud puts it on the official Google blog:
Many of us who knew him still find it hard to believe he’s gone. He died in 2005, but for six decades, Eisner was a participant in, and inspiration for, much of the best in American comics, as well as a friend and mentor to multiple generations of comics artists.
Eisner influenced comics in dozens of ways. In the ‘40s, Eisner’s The Spirit—a seven-page newspaper feature—introduced an arsenal of visual storytelling techniques still used generations later, and provided an early testing ground for future comics stars including Jack Kirby and Jules Feiffer. (The Spirit also began a tradition of pictorially-integrated logos—inspiring today's snazzy rooftop doodle!)