Hashtags don’t work well for social discovery because:

1. They can refer to multiple things. For example, when you use #apple is it for the fruit or company?

2. They’re unmoderated and can be used by anyone for whatever reason

3. They’re awful for long phrases

4. They can be easily spammed

5. They don’t actually signify “opt-in” but can just as easily signify something meta

The logic of “only use hashtags for discovery” falls apart in that search itself often requires context.

For example, #tea can mean many things.

Is it referring to the beverage or gossip?

Sometimes I want to use hashtags but I can’t because I acknowledge that a community needs to claim it.

Using hashtags in place of groups is a hack, and does not function well for social discovery.

Back when I was using Twitter, I wrote that Cosmic Crisp was the biggest launch in #apple history.

That statement upset a lot of people.

But I was referring to the apple (fruit) industry not the apple (tech) industry.

And I was meaning to share news for apple (fruit) fans—Cosmic Crisp was a big deal!

In this silly sense, hashtags failed me.