Jerff Atwood has a blog post entitled Google's Number One UI Mistake where he writes

Google's user interface minimalism is admirable. But there's one part of their homepage UI, downloaded millions of times per day, that leaves me scratching my head:

Does anyone actually use the "I'm Feeling Lucky" button? I've been an avid Google user since 2000; I use it somewhere between dozens and hundreds of times per day. But I can count on one hand the number of times I've clicked on the "I'm Feeling Lucky" button.
...
I urge us to Omit Needless Buttons. I hope the "I'm Feeling Lucky" button isn't considered a sacred cow at Google. Removing it would be one small step for Google, but a giant collective improvement in the default search user interface for users around the world.

A number of Jeff’s readers chimed in with the reason why Jeff is mistaken about this being a user interface “mistake” on Google’s part.

Robert Cooper wrote the following as part of his response

Google actually brought that up when they were user testing the UI a while back. (I can't remember where I read the story) But the crux of it was, the users actually LIKE having that button there, and rated the search interface lower when it wasn't there.

Geoff Wilson also validates the idea that this is on purpose in his response which is excerpted below

I remember listening to a google staffer on a podcast a while ago, and the reason the "I feel lucky" button stays is not its click through rates, but the message it sends about google's corporate culture.

Apparently, users felt Google was more human by having something quirky like that on the front page. It doesn't have lots of people click on it, but it encouraged more people to click on the main "Google Search" button.

and here’s one more comment excerpt, this time from Max

They can't remove that button now, it's part of their branding, part of their identity. They would be no more likely to stop updating their logo with colorful playful holiday-appropriate images (the shock of all that wasted bandwidth as proxy servers everywhere have to recache it!) than they would to remove that button.

Needless to say, the connection that branding builds between the user and the service/company is important. This button and the feeling of playfulness that it reflects on google even moreso. The few extra bytes of page size and the small extra cognitive load is more than made up for the positive feelings it engenders in users.

 Building a connection with the users of your software is important. There’s nothing like a little playfulness and humor to make your company and your software seem a lot more friendly to your customers.

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