CD Players – life of laser

Recently I read in a CD player user manual the manufacturer quoting “ switch off when not in use & save life of the player “. This has got me thinking as I have seen many threads opting for the source components to be permanently left-on. I have a few questions,

1)If the CDP is left ON with a disc IN the tray, does this consume life of the laser even if the CD is not playing.

2)If the CDP is ON with NO disc inside does the laser still work, again consuming life?

3)What do you normally do?

Thanks for your comments.
I can only say that playing life for (quality) lasers is usually spec'd at 100.000 hrs. That's a long time!
I don't know about ALL players, but for most, neither the laser nor the spindle motor is operating when a disc is in the machine but it is not playing and not left in "pause." Thus, the parts that more readily wear out, namely the transport and laser, are not operating. The rest of the electronics will remain on, which generally is not a wear and tear issue, unless your unit runs unusually hot or unless it has tubes in it.
I leave a disc playing 24/7. It's been 6 yrs so far. Considering the 100,000 hr rule Gregm mentions, I have at least 5 yrs and 5 mths left. By then I should really be looking at a new transport anyway.
My levinson 39 laser died after 5 years of fairly intensive use. According to the local service, this is not a unusual thing. Of course, there are may audiophile user, who plays music once a week a few hours. For them, laser-life could be 10 plus year.

Unless you are hoping for a Guinness book entry, what is the purpose of constantly running the player? It seems like "break in" mania taken to an extreme. Long before the whole thing dies, why wouldn't you expect performance to deteriorate -- the spindle bearing on the motor would begin to wear, causing wobble, etc?
Spectral SDR-3000

You will need to replace laser pickup and motor assembly in two years...average usuage...cost of repairs will be 1,000 or more. Figure this is bottom end...only upside.

The rule of expensive and lasting doesn't apply in all cases.
The laser and transport only work when playing a disc. The other aspects of the machine stay one and keep everything warm.