I know from personal experience, that trophies and achievements help sell games. I myself am a trophy whore on the PS Vita and PS3. I purchase or rent games that I normally would never play. Many times I find some really good games that I never would have thought of playing.
I also enjoy the added challenges to the games. I love looking at the trophy list, and dedicating more time in to that game, so that I can try to eventually unlock the Platinum trophy. Sometimes I join competitions to see who can gain the most trophies in a set time frame.
What do you guys think? Should Nintendo introduce their own trophy system? I personally think this is a must, and never should have been bypassed in the first place.