IndieGoGo definitely is a competitor for KS. They've had some huge projects recently and although people find their TOS sketchy, I find it to be far more honest. Yes, creators can keep your money if the project doesn't get funded. Yes, they are not bound to deliver the rewards.
The best part?
The site tells you explicitly that that is the case. None of that KS bullshit where it's "yeah the creator has to refund you if shit fails, but we offer ZERO ways of doing so! trololololo"
Over there, it's basically "if you want to donate, donate, but there is a chance you'll be screwed, and we don't care, so if you don't like that then gtfo."
They're less popular, and understandably so, but I have yet to see an indiegogo scandal where as KS is trite with them.
I mean, if you walk into Best Buy and the guy says "this TV is probably broken but you can buy it at full price if you want to" and then you buy it, and it's broken, you can't really blame anyone but yourself, can you? That's how I view IndieGoGo.
JSC seems very confusing to me, though. I don't like the sign up process at all.
A quick comparison:
Jump Start City
0 projects under "deck cards"
3 projects under "playing cards", all of which are still in the "elevator pitch" phase (Including one twice-failed project from Kickstarter).
Indiegogo
0 projects under "deck cards"
7 projects under "playing cards", of which:
4 failed with less than 10% of goal (one of which was a failed KS project)
1 failed with less than 75% of goal
1 succeeded - Zach Mueller's Fontaine deck, complete with tuck box print errors courtesy of USPC
1 is active - currently at 5 backers, C$69/C$6,000, and no art on the home page of the deck itself, which apparently is still in the early design phase. Dig deeper and you see three pieces of art, perhaps one of which even resembles a playing card (and only if you use your imagination). No deck back, no tuck box, just that. It's plain to see the project creator has never made a playing card project before, and did I mention that it's one of the infamous "flex funding" campaigns?
Kickstarter has had ten projects just in the past week...
From my perspective, JSC creates too many hurdles to cross for backers as well as creators, while IGG will have a hard time shaking its sketchy reputation - not that Kickstarter is all that and a bag of chips, either. KS has a veneer of respectability that's beginning to wear off due to its all-bark, no-bite "anti-fraud" policies.