I haven't read anything profound or non-obvious on this topic and there's a lot written about it.
The one thing I have learned creating and trying to get a 2 sided marketplace off the ground (https://gearoffer.com) is that it's excruciating, painful and nearly impossible.
The one thing you must have is perseverance. A lot of perseverance.
I can try to distill some of my own musings. I don’t know if they’re obvious or not.
1. Before launching a marketplace, grow a community interacting around content you get from free sources (or via a subscription) such as youtube, the web, restaurants, books etc.
2. Then link to existing marketplaces of sellers via an API (eg Amazon affiliates, OpenTable, Ticketmaster etc.)
3. Once you have enough people, build a more vendor-friendly sales process, reach out to vendors and see if they would list on you directly. Sometimes their contracts don’t allow them (eg with ticketmaster).
Now if you are intent on building a community from scratch, you will still need:
1a. A policy of subscribing to interests during onboarding (eg like with meetup.com) and telling people that they’ll get notifications as things are posted.
1b. Initially showing infinite scroll of ALL matching group activities around the user, with filters to filter it down by categories that have at least 1 result, so it never looks like a ghost town in most categories.
1c. Have subcommunities based on eg zipcode or city and let people grow them. For an example see https://yang2020.app/communities
1d. Have a system of credits users can earn for referring new users to the app.
1e. Leaderboard system per zipcode / week, who has the most credits. The leaders get some badges (digital goods) or even some real world goods.
Disclaimer: at https://qbix.com we build software for exactly this. Your job is to come up with the community idea, get the content license, get the various subcommunities, and we do the rest. We built https://yang2020.app for example, for Yang Gangs to unite. It lets you organize a local event/rally, rides to and from the event, checkins, and also uses some of the later Web features that finally work on all mobile browsers, like PaymentRequest (to pay for tickets) and WebRTC (to videochat or even screenshare). If you’re a developer it’s open source so you can grab it at https://github.com/Qbix/Platform and just build whatever on it.
The one thing I have learned creating and trying to get a 2 sided marketplace off the ground (https://gearoffer.com) is that it's excruciating, painful and nearly impossible.
The one thing you must have is perseverance. A lot of perseverance.