This an endurance event normally of between 100 and 250 kilometres which is becoming more and more popular and seems to have influenced an increasing number of road cyclists, which is definately a good thing.
In the UK, sportives are generally timed with riders starting in small groups within a start 'window', usually lasting 1-2 hours. In this country they are non-competitive challenge events. The finishing time achieved earns the rider a bronze, silver or gold award based on set time limits and age categories. There is no maximum time. They are a great way to challenge yourself and beat a personal goal.