Good question, but because Sony does not reveal this kind of information we can only make an educated guess based on the number of consoles we have repaired.
I think the average lifespan for a PS3 laser is around 1000 Hours which is not very much, considering if a person plays the PS3 for a few hours a day and some people are spending 3 hours or more per day on their PS3 consoles.
Here are the estimates based on our research, of course this information is based on a small portion PS3 owners and may not be a true representation of the real laser lifespan.
The laser lifespan can be increased or decreased significantly by several factors, see our guide on how to make your laser live longer.
Playtime Per Day = Days until Failure
1 Hour = 1000 Days
2 Hours = 500 Days
3 Hours = 333 Days
4 Hours = 250 Days
5 Hours = 200 Days