Many employers fear that major sporting events will lead to more absences from work. Making a bargain on watching an occasion like the Olympics would greatly reduce this risk and give your boss more certainty about getting work done.
Employers could also gain a huge amount of good will by accommodating requests to follow big events. Granting time off to watch sport could help to improve and maintain morale, which feeds through into productivity and the employer's bottom line. In practice, not everyone will be interested in watching, and as long as everyone’s interests are taken into account and normal service levels can be maintained, it can only be a win-win situation.