DVD writer limits?

Does anyone know how many disks you can burn on a DVD writer before it will stop working? I'm talking about hardware limits - not failures or dirty lazer heads. 1000? 5000? 10,000? Do companies post limits?

I don't think there is any real limit other than when hardware malfunction happens i have an 5yr old MSI 8x dvdrw drive thats still kickin it and burning as good as the day it was bought and probably done 7K odd burns and i have had and Asus dvdrw that stopped reading and burning 12mths after purchase as the laser died ...

Like most things mechanical they will eventually go Poo it just depends on the build quality better quality components in the build generally lead a longer life than cheap nasty

I was asking because I know that camera shutters have limits to when they have to be changed. 100,000 to 200,000 depending on the company. So I wanted to know if DVD burners had them too.