Currently there are two 4G LTE data add-on cards available, and they are priced as follows:
- $5 - 500 MB
- $10 - 1.5 GB
The extra data can be added to your account at any time, however, it only kicks in for use once your plans high speed allotment has been used up. Unfortunately, the add-on data does not come with carryover. Once you begin using it, you have to use it or you'll lose it at the end of your billing cycle.
Some TracFone owned brands such as Total Wireless, offer data add on cards that include carryover data, and with much better pricing. For instance a $10 add-on card with Total Wireless will get you 5GB of high speed data. However, Total Wireless does differ from Simple mobile in that it is powered by the Verizon network.
Perhaps a better comparison here is with Walmart Family Mobile, which also runs on the T-Mobile network and is also owned by TracFone. Walmart Family Mobile's data add on card is actually priced worse than Simple Mobile's, and it too does not come with data carryover. Walmart Family Mobile is charges $9.88 for 1GB of data.
I suppose the discrepancy between how the different yet related brands handle carryover data is related to their parent networks. It seems surprising to me that Verizon could actually be offering a better deal to its partners.
Carryover data is certainly advantageous to the consumer as the consumer will have the opportunity to actually use what they pay for. On the flip side, it's more profitable for the MVNO's and carriers to sell you data that you're less likely to use up. Given that carrier ARPU's have largely been on the decline for years, it's not a surprise to see some of them try and squeeze every penny out of you that they possibly can. I suppose though, that's just business in general.