I purchased a converter from them on 10/3, they billed my CC on 10/5 and was suppose to send me a voucher to get the item from an online vender. So far, after several emails to their support site, nothing has been done. I have removed the charge from my CC (thanks AMEX!) and have filed a complaint with the Washington BBB, and am in the process of telling anyone that would listen to stay away from Tippr. Looks like another scam deal site...
I suspect the positive comments are from trolls or Tippr employees themselves.