Do you use and pay for buffer and also like Nostr? Why not encourage them to support Nostr. 

This will mean something to them if you ARE a paying customer most, and secondarily if you would become one. If you’re not likely to use Buffer and pay them, then don’t post because that’s distraction for them instead of helping them know they’ve got paying current or future customers who want Nostr support.

https://suggestions.buffer.com/p/publish-to-nostr