Not sure. I know in my case I had my iPad active on tmobile (it is a tmobile iPad). Then I tricked Verizon with the IMEI provided above to activate a new SIM and now it all works good.
Didn't work completely for me
They ask you
1) Phone number -> got it from sim.
2) Device type -> clicked on tablet.
3) IEMI to see if you qualify -> used the one from this thread.
4) 20 digit code from the sim card -> entered it.
5) Plan type -> clicked prepaid
Finally got to the registration page for a new account.
I filled in everything, hit the submit button, and nothing happened.
I switched browsers and the same thing happened (i.e. nothing).
Did all of you who got it working already have a Verizon wireless plan for some other device (phone etc.) ?