Clubhouse, an audio-based social network with less than 5,000 beta test users, has closed an eyebrow-raising $10m round at a $100m valuation from famed US venture capital firm Andreessen Horowitz, according to multiple reports over the weekend.

Even by US standards, the valuation is lofty for such an early-stage company. But the app, which allows users to join open virtual rooms and listen to others have free-flowing conversations — you raise your hand to be invited to speak — has excited VCs and early users.

It has also prompted speculation about a new wave of startups which will spring up pitching “Clubhouse for X”, creating an audio social network based around a specific topic or interest-group. Here are some of the best that have been floating around. Will European founders be the ones to make them?

• Clubhouse for learning languages. Login and join ‘French’ or ‘Japanese’ or whichever language you are learning, speak with others better than you and immerse yourself.
• Clubhouse for gamers.
• Clubhouse for auctions — modern-day eBay.
• Clubhouse for narrating and talking about live events, maybe sports.
• Clubhouse for book clubs.
• Clubhouse for women / men’s circles etc…
• Clubhouse for business-to-business (B2B) sales. Dashboard shows which products are pitching and those interested can enter chatroom for Q&A / to learn more about product.
• Clubhouse for startup pitching.
• Clubhouse for Slack. Typing /ch in Slack, will open a Clubhouse session for a voice discussion among all Slack #channel members. Moving temporarily into vocal communication.
• Clubhouse for conferences, allowing events like TED Global or Slush to host both speeches and fireside chats online.
• Clubhouse for podcast hosts post-show/pre-show banter that fans can listen in on.

Clearly, the founders of Clubhouse — Paul Davison and Rohan Seth — are hoping that the Clubhouse of X will just end up being… Clubhouse. The app will likely end up with rooms for particular topics (running, cooking, golf, etc.), a bit like audio subreddits.

The people at House Party, Discord and High Fidelity — three apps in the audio-social sector — also might have something to say about who is going to end up dominating this area.

But it’s still an area that has some traction (or at least product/VC fit) and the “Clubhouse for X” is likely going to be seen in pitch decks for months and years to come.

For other Clubhouse for X ideas, put them in the comments!