Reason for 5000 Gmails

So what are some of the reasons someone would want 5000 Gmail accounts?

so many things... multiple account on websites, methods, need to do and confirm offers..

It all depends.

Gmail is the main email provider that does POP3 so you can forward all of the accounts to outlook. In essence if you have a few thousand, you have them all forward to ONE outlook account; then you go on your merry way posting ads and whatnot each with a different e-mail account and the confirm e-mails come to one account so you can activate the ads easily.

Some people need to be able to post more than one ad a day to CL or other places like that. A hundred accounts turns into a thousand, and then a couple thousand.

It's all above board...

I definitely know about the CL ads, I've done that sort of thing. Anyone who gets 5000 gmails at a time has to have some automation or outsourcing going on. What else would someone be using all those emails for, besides CL ads?