I know what they are. but why do we have them, and how do u use them?? What are the advantages and disadvantages?? and finally what effects do they have on the automotive trade??  thanx for anyones help

anyone

Well you kind of asked an ambigous
question, I don't think anyone has an
answer for you. If you know what these
are, why would you be asking about the
impact on the automotive trade

The impact of these programs is to help
mechanics solve automotive problems
and to keep the driver happy with a smooth
running engine, it's a matter of weather you
are reading one source or another, one might
have a better information database of problems
but I only know a little about Alldata, as a friend
of mine uses it

So, what is it you really want to know, you
didn't ask a logical question the first time.

Wild

The impact of these programs is to help
mechanics solve automotive problems
and to keep the driver happy with a smooth
running engine, it's a matter of weather you
are reading one source or another, one might
have a better information database of problems
but I only know a little about Alldata, as a friend
of mine uses it

Long, long ago you could buy the actual factory service manual for cheap because dealers sold cars and private garages serviced them. Now dealer service departments are the big profit centre and you can't get the actual manuals any more (or they are expensive). No small time service garage can affort all the service manuals from all the manufacturers. Alldata provides what the manufacturers won't.

Are there any pros and cons about them

Email addresses??