You can earn up to 10 GB of data by installing Globe Switch on your phone with a Globe/TM sim. Just claim all of the free offers that you see and there you have it, 3.2 GB per session multiplied by 3 (because you can only accept free offers three times). So in total you'll be having a 9.6 GB of data, but wait there's more. You can also get a 500 MB data for Facebook once you've sent "BONUS FB" to 8080 (this includes unlimited calls and texts to Globe/TM). Fair enough for a 30-40 pesos sim right? So, when you're done getting rid of the data of that sim. You can throw it away and buy another one and repeat the process.