While the Republic of San Marino has many hidden historical sights that are well worth visiting, the unhappy truth is that you have to dodge a lot of tacky souvenier shops to get to them. San Marino is chock full of cheesy souvenier shops and snack bars that are best avoided, as well as things like the Museum of Torture and the Museum of Curiosities, both of which belong in a carnival, not a country. In any case, while the capital is bad enough, the first few miles on the road from Rimini once you cross the rather ostentatious border into the Republic - the 'neon mile' - are worse. The truth is that, unless you are willing to look, parts of the capital, and almost all of what you first see upon entering the Republic, look dispiritingly touristy. Stay the course, it gets better!
Postcards with stamps! many people come to souvenir to get San Marino postal stamps. You can buy collections of them at all the kitschy souvenir stands. You can also buy pre-stamped postcards, which are stamped with 5 or 6 stamps are leave hardly any room to write, plus they are more expensive. I recommend that unless you came here for the stamps alone, then buy the postcards without the stamps and buy the stamps separately at the same place.
San Marino gets a lot of income from stamps and over the years has produced some outstanding issues commemorating events of local and Italian history and featuring beautiful philatelic gems that would honourably grace any collector's album. On the other hand, they occasionally produce a bummer, like this set for the Sydney Olympics. Looks more suitable for Little Miss Claven's Pokémon sticker book.
This is an example of local shops. You are invited inside in every shop, and it is done by all the languages from the world. As you can see on these picture, the name of this leather shop is written also in Russian language.
Visiting all the shop is not possible, so do not spend too much time on them. Unless shops are the target of your trip to San-Marino (In this case, just do not get crazy because of what you will see)