Some promos seem too good to be true, but there's always a method to the madness. (AMZN -0.17%) is teaming up with Kellogg's (K -0.47%) Cheez-It brand for an unusual marketing stunt. Amazon Prime members can enroll -- literally with just a click if they're already signed in -- for an offer that will deliver $5 in Amazon Prime Video credit and another $5 to be used for the purchase of Cheez-It product purchases through 

Of course there's a catch. You have to spend eight hours streaming select Prime Video content through the month of September. This won't be a one-off promotion, either. The instructions point out that you will have to reenroll every month for another $10 in Amazon credit, with a countdown clock already ticking down the days until October. It's a pretty crazy promotion. It's also pretty brilliant when you think about it.

A couple on a couch enjoying content on a mounted TV.

Image source: Getty Images.

Searching for clues -- and Clue

This would be a painful chore if you had to stream obscure and dreadful content to make the equivalent of $1.25 an hour in credits, but the first batch of select titles is surprisingly decent. Amazon is rolling with a back-to-school theme with 15 available movies that help qualify for the viewing requirement. You have some throwback cult classics including WarGames, Heathers, and Clue. You also have a rather recent theatrical release on the list in Dora and the Lost City of Gold, the Dora the Explorer live-action update that hit a multiplex near you last summer. 

It's not clear if any of the film studios behind the September content requirements are shelling out money to be a part of the select list, but it's pretty clear what Amazon and Kellogg will be getting out of this. For Kellogg it's fairly obvious. Its Cheez-It crackers recently rolled out Snap'd, a line of thin and warped cheese crackers. It's spending a fair amount on digital marketing for Snap'd, so teaming up with Amazon for $5 in store credit for customers to get a taste of the new offering makes sense.

Amazon has even more to gain here. It began the year with more than 150 million Amazon Prime members, but Prime Video is often an afterthought in the streaming video hierarchy. Amazon includes a growing amount of digital content at no additional cost to current members of its Prime loyalty club. It also sells and rents streaming movies and TV shows that aren't part of its Prime Video catalog at an additional cost.

The world's leading online retailer wants you to spend more time leaning on its digital goodies. It will routinely offer a buck or two in digital vouchers that expire in a few weeks in exchange for folks accepting slower deliveries of physical product orders. A $5 offer is fairly generous, but worth it if it gets you into the habit of leaning on Amazon the next time a major premium video on demand release hits the market. 

Amazon isn't desperate. It just saw net sales soar 40% in its latest quarter, its headiest top-line surge in two years. It's the class act of retail stocks, and it's currently the country's second most valuable company in terms of market cap. If Amazon wants to shell out $1.25 an hour in snack food and content to consume while you're crunching away on Cheez-It Snap'd crackers, it knows exactly what it's doing.