I'm actually totally ok with receiving "wallet spam'". Spam money at my wallet all you want! Ha! But I do ask that you send at least one Steem penny or 0.01 SBD when you do. Sending a smaller amount than that will annoy me.
I feel like I should ask for more, but that starts to seem arrogant.
Edit:
Wallet spam is sending small amount of money to someone's wallet with a message, usually to check out a post of theirs.