Even though some of the so-called tricks Venetian restaurant and café owners use to take extra money out of tourists are quite a normal occurrence in Italy, for most tourists it is unheard of and unacceptable in their countries.
There are two different ways the owners of restaurants and café shops use in order to take a little extra money out of tourists: difference in prices in case one sits or stands and coperto (an additional fee). Most Italians are used to these two things, because it is a normal occurrence in many other regions in Italy, but for most tourists they are unheard of and create altogether unpleasant situations.
Different prices in case you sit or stand
The trick is that owners of restaurants and cafes have completely different prices in case a customer decides to sit or stand. Most Italians are used to taking their coffee and a brioche standing at the bar. On the other hand, in most other cultures it is usual that people sit for a while and enjoy their drinks. This is especially a problem in Venice, because the difference in prices can be really substantial and because in the city there are just a few benches and places where tourists can sit and rest for a bit. The local authorities would claim that they did not want to occupy already limited space, while tourists would argue that it is because they wanted to boost the local economy and make tourists have a drink and rest in numerous restaurants and cafes. In any case, because of the lack of benches in Venice, tourists are almost forced to make a break and sit every hour or so, because of extremely warm summers in the city and of course the effort of walking for the whole day.
Because of everything mentioned in most cafes in Venice, as a tourist you will be offered to sit before you order anything.
This is a completely separate charge on the restaurant receipt you receive. It is a compensation for the cutlery the restaurant provided and for the table you occupied. Most restaurants in the city have menus with prices exhibited at the entrance, but in a very small print at the bottom of the list you will be able to see the word Coperto and how much it is. This charge is for each person separately and it is not for the whole table. Coperto varies from restaurant to restaurant and it is usually from 1.5 to 3-4 Euros per person.
It is not rare to witness arguments between customers and employees of a restaurant regarding Coperto. The argument is never about whether the customers can afford it, but about the principal that the information was not well displayed and that these things are unheard of in most countries in the world.