Horizon Card Services is no longer marketing Principal Platinum. We suggest these alternatives instead.
Boost Platinum
Apply Here 
Boost Platinum is another card by Horizon Card Services with identical terms. No credit checks and $750 credit lines to start. Note: Boost Platinum has stopped reporting to any credit bureau so we recommend Extra Debit Card instead if you are looking for an online store card that is guaranteed approval and also to rebuild your credit.
Extra Card
Apply Here
Both Principal and Merit Platinum used to report to Equifax but they no longer report to any credit bureau. If you are looking to rebuild your credit, Principal and Merit Platinum will not help you. We suggest you consider the Extra Debit Card. It is one of the rare debit card that reports to both Equifax and Experian. There are no credit checks and you will be approved as long as you have a checking account. The monthly fee of $20 is lower than the $24.95 monthly fee of Principal Platinum. You also get to use it everywhere Mastercard is accepted and your credit limit is determined by how much you have in your bank account.