Building a 2-Sided Marketplace?

I just started a project to help an IndieHacker who is building a 2-sided marketplace - could be a shortcut for LOTS of IndieHackers out there!

My buddy was about build a messaging tool so buyers and sellers can communicate - without having each other's email address and phone number. Now, he doesn't have to. We plugged in my existing tool (ContactLink) and now he can finish the project much faster.

His marketplace lets Clients find the perfect Advisor (can't say more since it's not released yet). When a Client gets matched with an advisor, he hits an API on my side, and we generate a URL.

From that ContactLink URL, the Client can video call, text message or secure email the Advisor to get the conversation going. Or, schedule an appointment for later. The advisor gets their voice and video calls, messages and attachments in my App on their iPhone or Android.

It's a pretty simple integration. The Advisors become ContactLink free members, and then my buddy's website hits our API to create the Conversation URL for the Client to use. He just passes us a name and email address for the Client, and the ID of the Advisor they will be talking to.

Anybody else need a tool for communications for a marketplace? This approach lets you stay in control, since your buyers & sellers don't have each others contact info. It's also more reliable, unlike phone & email where you're not sure if the other person got your message. You can learn more about the toolset at www.ContactLink.com

Let me know if you can think of other places a tool like this would be useful!