Amazon's Diaper.com play: The latest effort to become part of your household

Amazon will reportedly buy Quidsi, parent of Diaper.com and Soap.com, in a move that highlights how the e-tailer wants to become a regular part of your household purchases.

According to Fortune and the Wall Street Journal, Amazon will officially announce its purchase of Quidsi Monday. The commerce giant is best known for music, books and other items, but groceries and everyday goods---the stuff you'd buy at Wal-Mart or Costco or any grocery store---are increasingly in play.

By buying Quidsi for roughly $500 million or so, Amazon builds on its plan to attract moms, who control a big chunk of household purchases. A URL like Diapers.com goes quite nicely with Amazon's Baby Store, which gives caregivers and parents a 30 percent discount off of purchases.

And Amazon's master plan goes well beyond just diapers and soap. Amazon is increasingly playing with grocery subscriptions. For instance, I get tea shipped to me every six months for a 15 percent discount.

You can do the same with other household goods.

Any trip to Target or Wal-Mart highlights a wider grocery selection. If you start buying groceries at these retailers, chances are your shopping frequency will increase and so will your spending.

Amazon is looking to play into the same theme. The Quidsi buy may be about some intellectual property, but ultimately Amazon is looking to play the demographic and shopping frequency game.