Stupidity is contagious. It gets us all from time to time. Even respectable companies can catch it. Let's take a look at five dumb financial events this week that may make your head spin.

1. Mr. Softy doesn't make sense
Microsoft (NASDAQ:MSFT) CEO Steve Ballmer turned heads yesterday when he noted that a combination with Yahoo! (NASDAQ:YHOO) would "make economical sense."

Microhoo revisited? Yahoo! shares soared on the news, which means that this dumb stock move will go one of two ways. If Ballmer is serious about going after Yahoo! again -- which I doubt -- he just shot himself in the foot by pre-announcing his plans. Now that speculators are chasing the stock higher, he won't get as good a deal as he could have by quietly approaching a depressed Yahoo!.

Since Ballmer is unlikely to be that boneheaded, the dummies are probably the investors who began snapping up shares of Yahoo! based on the buyout buzz. Don't get me wrong. Yahoo! is an attractive buy here. Traders just better make sure that they are buying for the right reasons, not the heartbreakingly orchestrated ones.

2. Lost and found
Speaking of Yahoo!, the company's blog introduced a new marketing campaign, seeking to emphasize the company's search engine superiority. It's a smart approach. However, the display ad it's rolling with actually takes a shot at Google (NASDAQ:GOOG). The ad features a "Lost" poster on a pushpin board, followed by "last seen searching Google for energy-saving tips."

Attacking Goliath is a common marketing practice, but isn't this the same Yahoo! that is turning to Google in outsourcing its paid search ads? It's hypocritical at worst, and the key to clammy handshakes at best.

3. Cheap iPod killer is barely an iPod tickler
Flash memory titan SanDisk (NASDAQ:SNDK) is introducing a $20 MP3 player. If that sounds like a wonderful price point, let me tell you a little more about the Sansa slotMusic Player. It has no internal memory, since it only plays music from microSD cards. I'm talking about tiny rewriteable memory cards that can get lost in your pocket. SanDisk is teaming up with major label artists to put out slotMusic albums, complete with liner notes and album art, but don't confuse the bonus features with something you can use on your player. It doesn't have a screen!

Did I mention that you don't ever need to recharge your Sansa slotMusic Player? No, that's not good news. You need to replace the AAA battery inside when you go through less than 15 hours of playtime. Some have argued that SanDisk knows what it's doing. It must have spent a ton of time and money in testing the slotMusic viability. So? Tell me that this doesn't sound like clearance bin fodder by next summer.

4. While my DVD player gently weeps
Playboy (NYSE:PLA) is taking it off, and not in a titillating way. The adult entertainment icon is eliminating 80 positions at the company, shuttering its DVD division as it turns its attention to digital distribution.

This strategy would have made perfect sense 36 centerfolds ago. These days, there are too many free websites out there giving smut away. Despite its best efforts, Playboy's online revenue has been stagnant in recent years because of the competitive climate. The same can be said for the company's raunchier competition. So what is Playboy doing exactly? It is getting rid of the physical product that bunny-chasing consumers are willing to pay for, to pursue a crowded arena where traffic gravitates toward freebies? Bad move. What's next? Turning the signature mansion into a day-care center?

5. We're all bears, now
I'm never a fan of press releases that have a roundabout way of getting to the bad news. Yesterday's Build-A-Bear Workshop (NYSE:BBW) quarterly release did exactly that. Bullet points at the beginning praise the stuffed animal retailer's growth in Europe. It isn't until later that you find out that Europe accounts for less than 18% of the company's net sales. Comps at its more significant stateside stores actually fell by a sharp 14.4%.

The company is also shuttering its "friends 2B made" concept, offering customized girl dolls. Think Bratz or Mattel's (NYSE:MAT) Barbie, only fabric-based. I was keen on the concept when it debuted more than three years ago, but the company never put the marketing muscle behind the product or gave it enough Bratz-esque personality pizzazz to make it work. Still, I think it's a mistake to cut the cord on the concept. It places all of the company's eggs in its plush bear basket, a niche that it is cheapening by offering more of its stuffed critters at its entry-level $10 price. We may be in a bear market, but not a Build-A-Bear market.

Let's beat the dumb drum:

Microsoft is a Motley Fool Inside Value selection. Playboy and Google are Motley Fool Rule Breakers recommendations. Try any of our Foolish newsletters today, free for 30 days.

Longtime Fool contributor Rick Munarriz is a fan of dumb and smart business moves. Investors can learn plenty from both. Hdoes not own shares in any of the stocks in this story. Rick is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool has a disclosure policy.