[edit 6/18/13: It looks like I have an affiliate link for the basic AccountNow card as well. If you are interested in using AccountNow, and want to support the site and the work I do here, feel free to use this link. See the comments below for some of the risks of the technique described here.]
Regular readers of this blog know that one of the simplest ways to manufacture spending on rewards-earning credit cards is by loading Vanilla Reload Network reload cards directly to a Bluebird account, which can then be used to pay bills, including credit cards. This has the advantage of being simple, predictable, and low cost - many rewards currencies are worth manufacturing at 0.78 cents each, and that's before taking bonuses into account. However, Bluebird loads are limited to $5,000 each month, which led travel hackers to seek out similar products.
A slightly more expensive technique that I discovered and reported out is loading a Gobank account with a reloadable debit card, like the MyVanilla Debit Card. This raises (but doesn't eliminate) the limit on the amount of manufactured spending you can do each month, but also raises the cost, since MVD cards charge $0.50 per swipe transaction. Still, at 0.84 cents (a $1,000 load, for simplicity's sake), this is still a great way to earn rewards.
A third, even more expensive version of the same technique uses AccountNow, a reloadable, prepaid debit product (not a checking account). Jason Steele over at The Points Guy reported on AccountNow in the context of Green Dot MoneyPaks – if you're able to buy those using a credit card, then AccountNow is only slightly more expensive than Bluebird (since MoneyPaks have a $4.95 load fee, rather than Vanilla's $3.95).
If you don't have access to MoneyPaks, you can still load your AccountNow account at Walmart using their Rapid Reload Network. However, there is a $3.74 load fee for swipe reloads of AccountNow. The maximum daily load is $1,500 and monthly maximum on total loads is $9,500.
Using my technique of loading MyVanilla Debit Cards with Vanilla Reload Network cards, then unloading them to AccountNow, your total out of pocket cost will be $16.09 ($11.85 in Vanilla Reload fees, $0.50 MyVanilla transaction fee, $3.74 in Rapid Reload Network load fees) for $1,511.85 in manufactured spending, or 1.06 cents per dollar.
On the one hand, that's much more expensive than other existing techniques to manufacture spending. Other than free techniques like Amazon Payments, my cheapest manufactured dollar is 0.185 cents (using the technique I pioneered here). So the question isn't whether it's worth manufacturing every dollar at 1.06 cents each; the question is whether it's worth manufacturing your last dollar at 1.06 cents each.
That will depend on your specific situation, and especially on whether you have access to Vanilla Reload Network cards at merchants that are bonused categories for your rewards-earning credit cards. All that said, I think there are certainly situations that can make this technique worth using, and I wanted to make sure my readers were aware of it.