Free first month to add a line

When it comes to affordability in the wireless market, Cricket Wireless beats 'em all. We have seen the prices the carrier offers for years, and now they have the "add-a-line" deal where existing Cricket customers can add their "already-used" Cricket handsets and have first month of service for free. Can anybody beat it? I don't think so. The only fee required is a $15 fee that stores charge when adding a line. So, its a great bargain.
While customers can get a whole month of service for free, they can also make use of an old handset that is just sitting in the house to get rotten. So, this is the advantage side. Any drawbacks? None, however, some need for education on the customer side.
What I have noticed so far about this plan is that when Cricket sends the text message about the "add-a-line" promo, they think that they would need to pay only $15 a month for the second phone that they want to add on to the account, which is not true. The $15 is a one time fee at the time customer adds a phone to an existing account, however, starting next month, the customer needs to pay for the plan that he has chosen to have on that phone, which could be $35, $45, or $55 depending on the features on the plan. So, customers need to be properly educated about this issue, because I have seen customers cursing after the second month saying "It is a rip-off, I thought it was $15 a month." It is not a rip-off, it is marketing on one side, and kinda deal for the customers as well, which one cannot get always without having to sign a long-term contract or having to check the credit score.
Other thing customers need to be educated about is what happens when one of the account holder does not pay the bill that he is responsible for. A lot of customers add a line for $15 without thinking long term. They simply add the phone because it is only $15, and when it comes to making the payment ultimately the next month, they do not make the payment on that account resulting in suspension of both the line. So, customers need to be advised on this part as well.
Everything has two sides, good and bad, and this offer definitely has all GOODs, provided the customers are educated.