The sales world seems to be in a state of constant change, thanks to the emergence of new technologies.

To explore the most pivotal inventions that have revolutionized sales, Lattice Engines created the following infographic. It starts with Johannes Gutenberg's invention of the printing press (cuneiform and papyrus didn't make the cut) and brings us up to today.

Among the highlights:

1870s: Alexander Graham Bell invents the telephone. This invention greatly diminishes the world of door-to-door sales.

1980s: Laptop computers begin to transform the day-to-day tasks of salespeople.

1990s: Email's popularity now helps salespeople reach buyers in new, interesting ways.

1990s: Virtual meetings let salespeople connect with clients without their having to physically leave their offices.

2002: The emergence of smartphones, such as BlackBerrys and Palm Pilots, help sales reps access data and close deals while on the road.

Check out the infographic for even more highlights from the tech side of sales: