Verizon's prepaid smartphone plans are a great deal, assuming you don't mind not having the absolute best phones and you can forgo 4G LTE data speeds. At $60 for 2GB and $70 for 4 GB with unlimited talk and text, the monthly service rates are hard to beat for an individual user.
But what if even 4GB isn't enough data? Or what if you run out of your 2 GB in the middle of the month and you don't want to come up with a full $70 to start the new plan in the middle of the month? One option is to buy a single gigabyte for $20. It's not a great deal, but not bad either.
Now another option is available: Kickbit. Kickbit is an app available for Android and iOS phones and tablets. Take surveys, play games, test other apps, and watch promotional videos to get extra data added to your account. Keep in mind that downloading the app, taking surveys, watching videos, and downloading partner apps all takes data, so be sure to connect to wifi while using Kickbit, or plan ahead and start running the app to rack up spare GBs before you run completely out.
If you look at the promotions in the picture, some of them require signing up for Hulu or Gamefly, which means that even the free trial would require a credit card, and obviously a video streaming service like Hulu will take significant amounts of data. I used a similar app to generate credits for some "freemium" games, and it seems to work well. Remember with your free trials that once the free promotion period is over, you will be billed for the service as a regular customer.