Either the South Korean multinational didn't have enough spare handsets, or there are too many Apple users wanting to make the switch, or both - after just a couple of days the demand has exceeded supply and the scheme has been put on hold.
"Due to the overwhelming demand, we are temporarily out of test drive phones," reads the note on the Ultimate Test Drive site. "Please keep checking back for available phones."
Try before you buy
Through the terms of the original deal, interested users are able to get a month's data plan through Verizon, AT&T, T-Mobile or Spring. You can only register for the trial from an iPhone so Samsung knows you really are keen on giving Android a spin.
You then have a 30-day period to try the phone, and can return it before the end of the month with no questions asked. If you decide to keep it, your credit card gets charged the full price of your chosen handset.
If the experiment really is getting people to make the switch then Samsung is going to want to replenish its stocks as soon as it possibly can - the next batch of iPhones are due to be unveiled by Apple in September.