If not already done, print up a load of PoS stickers and include free with every shipping from Nimiq shop.
Nimpay or another pos pwa hopefully in development for vendors but even before then would great to see more of these in shops and cafes!
2 master files in illustrator if anyone wants, accepted here in muli font as per styles.
8x3 inch wide 300dpi
3x3 inch small