I understand that printing and distributing fliers is an obvious choice for an offline strategy however, especially in the beginning, I am thinking of possible multi-use strategies.
One of such I have mentioned in the chat and that is, what I got to know, in English called beer matt. These are multi-use long-lasting high-exposure if placed in a touristic pubs. And most pubs would just distribute them for free because they tend not to care.
Another multi-use strategy is to use stickers and put them on the maps of underground, buses and trams.
Any other ideas?
Sounds really good to me @Sergej Novik ! I would start with the beer matt's ... and try it out in your town ... were are many cafe's and restaurants ... after you gain some data over time ... I would make a step further and get in closer contact with this cafe's or pubs ... and discuss further steps were they would profit as well !
I really like this idea. After a few beers, people let "let their guards down" and are more likely to try stuff. A beer mat or coaster with a QR code and short catchy phrase could work really well!