You are looking for tickets for a major sporting event or a popular artists concert. The event sold out within minutes on the official sellers website but you notice plenty of tickets available on other websites. How can this be possible? Secondary ticket sellers buy up tickets for the events and then sell them for inflated prices. Sometimes they could be overselling so you may not end up with a ticket to the event. It is buyer beware when purchasing tickets for sold out events as they are usually sold out for a reason.
Remember! It is illegal for any company to sell tickets to a football match in the UK without the prior authorisation of the event organiser