Mayer Rolls the Tumblr Dice

NEW YORK ( TheStreet) -- From the get-go, I strongly supported Marissa Mayer's tenure as Yahoo! ( YHOO) CEO. While I still believe in the legend of Mayer, I'm officially jumping off the bandwagon.

YHOO stock is up 70% since Mayer got the gig. If you have been long, get the hell out. Even if you miss a bit more upside, why be greedy?

It's not that I dislike Tumblr. It's a perfectly worthy fad among a whole slew of new entrants into the space, if we can call social microblogs a "space." It's just that a.) I do not see the sense in making the acquisition; b.) it makes me feel like Mayer has too few original ideas on how to rebuild Yahoo!; and c.) everybody is on the bandwagon like a pack of blindfolded sheep.

Over at Fortune, Dan Mitchell had the best take yet:
The reaction to Yahoo's acquisition of Tumblr is way out of proportion to its importance. It could be a relatively small mistake or a marginal gain.

His article is well worth your time. It sums up so much of what I think of the deal, even if he is a bit more optimistic and forgiving than I am.

If Mayer feels like she needs Tumblr, at over a billion dollars, to raise Yahoo! from the dead, she's not nearly as talented as I initially thought. There's no need to blather on and on about. I stop by asking the obvious question ...

Mayer still has loads of traffic coming to Yahoo! properties every day. And she can't find ways to monetize this traffic and push it over to mobile platforms. She needs to purchase, as The Onion put it, "millions of blogs written by 13-year old girls."

This is what the brightest and sharpest tool to come out of the garages of Silicon Valley since Bill Hewlett and Dave Packard brings to the table?

I'm not excited. And Mayer sure as hell did not help evolve the co-mingled worlds of media and tech with this deal that people -- the same people who nauseatingly gushing over it now -- will be ripping this time next year, if not in a few months.

Mayer told the world Yahoo! won't screw Tumblr up. Tumblr founder David Karp told his people "F*** yeah"! Tough to blame him.

But, soon we'll be saying Look out below. This move is about as unimaginative as it gets. It only provides further proof that Mayer has no confidence in what she has at Yahoo! and no clue as to what to do with it.

-- Written by Rocco Pendola in Santa Monica, Calif.
Rocco Pendola is TheStreet's Director of Social Media. Pendola's daily contributions to TheStreet frequently appear on CNBC and at various top online properties, such as Forbes.