Amazon got set to announce another acquisition this weekend. The target this time is a company that uses complex algorithms to deal with baby poop. Amazon is looking to buy Quidsi, the company that owns Diapers.com, for $540 million.

I don’t have any children, but I still know that diapers are about as hot a topic among new parents as the impending Call of Duty launch is among fifteen year-old boys. Quidsi is of particular interest to Amazon because of its technical approach to problems like stocking shelves. One of the company’s founders told Inc. last year:

So before we launched, we built proprietary software from scratch. We built software with computational algorithms to determine what the optimal number of boxes to have in the warehouse is and what the sizes of those boxes should be. Should we stock five different kinds of boxes to ship product in? Twenty kinds? Fifty kinds? And what size should those boxes be? Right now, it’s 23 box sizes, given what we sell, in order to minimize the cost of dunnage (those little plastic air-filled bags or peanuts), the cost of corrugated boxes, and the cost of shipping. We rerun the simulation every quarter. Using the right box probably adds close to 1 margin point.

Sound familiar? That’s exactly the kind of thing that helped Bezos make a name for himself. It’s also how Zappos, which Amazon also acquired not so long ago, ran their online shoe store.

The crazy part of the deal, though, is that Amazon paid $200 million over the company’s most recent venture valuation. I’m not sure why, unless they really wanted to be sure they were the ones to get it. Apparently Wal-Mart had also been sniffing around Quidsi.

Source: CNN Fortune

This morning Amazon announced that it had closed the Zappos deal that had been rumored since July. Originally the online shoe retailer was valued at $928 million, but the final sale price was a whopping $1.2 billion. Yeah. With a B.

Zappos was happy to announce the news as well, stating that investors were compensated for Zappos shares with Amazon shares totaling the sale price. Zappos CEO Tony Hsieh also pointed out that things will pretty much stay the same with regard to management, albeit with a few new faces around.

We’ve been spending the past few months obtaining all the proper government approvals, and I’m happy to say that we officially closed the deal at the split second between Halloween (10/31/09) and All Saints’ Day (11/1/09). From a practical point of view, we’ve switched out our previous board of directors with a new management committee that is composed of people from Zappos as well as Amazon.

All in all, a pretty good weekend to be in either camp here. For Zappos, you just got $272 million richer. For Amazon, you just picked up a company that sells a billion shoes a year. Yeah. With a B.