Here's an evernote file of things I've found and liked around the internet re: 2 sided marketplaces. All digital, although not sure exactly how "successful" they are - but more for reference.
Quality / Copywriting https://www.yourmechanic.com/works#mechanics https://www.airbnb.ca/?locale=en http://powhow.com/
Community Engagement http://www.houzz.com/ideabooks https://www.healthtap.com/ https://www.airbnb.ca/wishlists/popular https://www.wello.com/class/set/Yoga/
Categories / Search http://www.etsy.com/ http://fiverr.com/ https://www.airbnb.ca/s/moncton?source=hdr http://takelessons.com/search?q=4gq30T
Deliver of Service www.hotelstonight.com www.uber.com https://www.medicast.co/ www.wello.com www.takelessons.com www.taskrabbit.com
How it works https://www.taskrabbit.com/how-it-works
https://www.zaarly.com/howzaarlyworks http://takelessons.com/students/how-it-works https://www.wello.com/how-it-works/ https://www.medicast.co/how-it-works https://www.healthtap.com/#how_it_works https://www.wello.com/how-it-works/ https://www.odesk.com/info/howitworks/client/ http://www.guru.com/emp/takeTour.aspx
The Why http://nest.com/smoke-co-alarm/why-we-made-it/#nobody-ever-looks-up
Supply Side https://www.elance.com/q/find-work
http://www.guru.com/pro/index.aspx
https://www.odesk.com/info/howitworks/contractor/
http://takelessons.com/teachers
https://www.zaarly.com/selling http://www.skillshare.com/teach https://www.udemy.com/teach/ www.powhow.com/open-your-own-studio https://www.airbnb.ca/rooms/new
Conversions http://www.justanswer.com/ http://www.skillshare.com/
Referals http://www.powhow.com/open-your-own-studio uber.com/invite/rjif2
Subscriptions http://www.powhow.com/open-your-own-studio http://premium.docstoc.com/subscribe/plans http://www.rocketlawyer.com/plans-pricing.rl
Help Center http://help.zaarly.com/ https://www.airbnb.ca/help
Pricing http://www.rocketlawyer.com/plans-pricing.rl http://www.powhow.com/open-your-own-studio http://premium.docstoc.com/ http://mixergy.com/premium/ http://wistia.com/pricing https://teamtreehouse.com/subscribe/plans
This Nov 2012 blog post by Bill Gurley of Benchmark Capital is very insightful, and cites some great examples as well:
All Markets Are Not Created Equal: 10 Factors To Consider When Evaluating Digital Marketplaces http://abovethecrowd.com/2012/11/13/all-markets-are-not-created-equal-10-factors-to-consider-when-evaluating-digital-marketplaces/
Also, see the deck here which takes Bill Gurley's ideas above and translates them into an evaluation framework: http://www.nirandfar.com/2013/03/making-a-marketplace.html
A friend of mine started http://www.apptopia.com/. You can judge success from your own lens.
Is eBay not a great example of a 2 sided marketplace?
