Yes. I use one for https://😁.to and we also have https://🚧.to for WIP.

Pros:

• It's fun and makes you stand out from the crowd
• It's short
• Depending on the emoji it might be easy to remember

Cons:

• Many browsers including Chrome don't show the emoji in the domain name
• Technical support is lacking (e.g. I believe Slack doesn't auto-links emoji URLs)
• It can be confusing to people unfamiliar with emoji domains
• It probably doesn't help for SEO purposes
• You're limited to a non-standard domain extension

Overall I would recommend using them only as a redirection URL (like 🚧.to), or when standing out outweigh the cons (e.g. for silly side projects).

Agree with Marc's overall conclusion. Another con is that you can't share emoji domains on Facebook (doesn't recognise as a URL).

Agree with all points as well.

One thing that is a little unknown but good to be aware of: On windows, one can use the "windows key + dot" to make the emoji pop-up appear.

This can be good in marketing. But it is better to have the main domain of ordinary letters for SEO and normals.