Welcome to the platform. It does not matter if the accounts are large or small you can say thank you to anyone. @stach would probably be considered a community or curation account which is ok. It is a larger account, there are very few on here above 500SP and they are over 5000SP. They did well selecting your post, that's pretty cool. I would say engage lots, but that's hard to do at 15SP. I'll poke around and see what I can do.