Website:Book directly on the VivaAerobus website
Wikipedia:See VivaAerobus's Wikipedia page

Cheap fares, cheap service, cheap planes. You get what you pay for. The planes are dirty. They charge for everything that is imaginable. You must purchase your tickets months in advance in order to obtain the low priced tickets they offer. But, if you do, you face the fact that they constantly change the flight schedules after you have purchased your ticket, and if the new schedule does not suit your needs, they charge to change your flight and will not issue a refund if their "new" schedule no longer suits your travel needs. You better not be more than 5 ft 6 in tall or you will not fit into their extremely cramped Boeing 737 seats. At the end of the day, if you obtain one of their cheaper tickets, you cannot beat the fare. But, buyer beware, tons of headaches and grief are also part of the cost that you will pay.
Avoid school holidays: Many cheap airlines take advantage of school holidays to increase their prices, as they expect to have a larger number of passengers than usual. During these periods a late booking (1 week before departure) may result in your paying more than the price of a ticket with a regular airline. It is therefore advisable to avoid these periods, if possible.