advantages:

-you may meet a lot of interesting and kind people

-it should be very poor to travell like that

-I think that it`s more comfortable than in the long-distance buses

disadvanteges:

-you may meet a very cruel or person or just a murderer or somebody like him

-it should be very poor to travell like that but I prefer to pay money and to travell with some comfort in a train or in a plane

-I suppose that if during your travelling something would break (for example,a car) nobody will help you but if you have  ordered a ticket in a company which deals with travellings, you may hope for help or to demand your money back