On most bus, tram and light rail systems in mainland Europe (and in many other parts of the world) they either have ticket machines at some or all stops, or else you can buy a ticket on board the bus or tram either from the driver (or conductor, though crew-operated buses and trams are very rare nowadays) or from a machine.
But I think there are some networks that do not have ticket purchase facilities either at the stops or on-board, so you have to buy a ticket from one of the various outlets that sell them (e.g. convenience stores, newsagents, tobacconists, tourist information centres, hotel and hostel reception desks). How many networks do you know of where this is the case?
It can be a real pain if you have to go out of your way to find a ticket outlet or if you arrive late at night when no such outlets are open so you have to take a taxi which costs you more than the bus or tram would cost if you could get a ticket.
But I think there are some networks that do not have ticket purchase facilities either at the stops or on-board, so you have to buy a ticket from one of the various outlets that sell them (e.g. convenience stores, newsagents, tobacconists, tourist information centres, hotel and hostel reception desks). How many networks do you know of where this is the case?
It can be a real pain if you have to go out of your way to find a ticket outlet or if you arrive late at night when no such outlets are open so you have to take a taxi which costs you more than the bus or tram would cost if you could get a ticket.