it's a great incentive for players to watch their own progress, and encourages repeat usage.
also, seeing leaderboards at locations is cool too, and encourages some healthy competition.
I agree. I think it adds a lot on location, You see players checking the leaderboard when they walk in or after they (or someone else) puts up a good score on one of their favourite machines, and a lot of conversations are struck up because of the leaderboard. Ottawa Pinball Arcade added a D & D about 10 days ago, and there's been a lot of people have come in to play it that are infrequent or new visitors to the arcade. I'm sure IC must have been how many of them found out it was there. I've also visited a couple of one or two-table venues purely because I saw they had an IC machine I'd never played. So I think it must be added value for operators.
I've definitely found that it sometimes influences which machine I play at an arcade (eg If I've dropped down the leaderboard a few spots, but I know that the scores above me still below my best ever, or there is a new leaderboard up for the month or the quarter and I want to put a score on the board.)
I liked the achievements on Foo Fighters and Bond, and they helped me to improve on those games by learning a bit more about the rules for specific aspects of the games. Most of the games since Jaws onwards seem a bit light in achievements compared to those two, which is a shame.
The badges don't resonate with me as much, they seem a bit random, but I think in general IC is a great tool for keeping track of your scores and progress on games.