As the cornerstone of our interaction with the internet; search has become the most profitable enterprise in the domain. Consider that almost every foray we make into the information wilderness begins at a search box; any time we're not already familiar with our destination we start there. I'll wager there's a very high likelihood your browser's starting page is a search engine. I'll even go so far as to say your browser's starting page is Google search.
In fact, google has become a verb, synonymous with search it has become common parlance among web users and nerds the world over. Google is a behemoth not without it's rivals, and I've picked three to compare. Success in the search engine space seems to me to be tied into the simplicity of it's interface. Google's debatable primary rival in this domain, Bing, seems to be learning this lesson while the ageing giant Yahoo! has missed the message and is getting left in the dirt.
I suspect that Yahoo! suffers from it's own legacy. It is one of the few remaining survivors of the early internet portal generation, where much of the enterprise and professional level content could easily be centralised. Internet commerce was in it's infancy and high-bandwidth media such as video was a rarity.
The Yahoo! front end is still brimming with options, affiliations and services but truth be told it offers little or indeed nothing that it's rivals do not also offer. The only real difference here is Yahoo's desire to push everything at you immediately. Yahoo's need to market itself has been given precedence over the user's intention. The action of searching has been encroached upon by innumerable other things that Yahoo would like you to do with them. It's a little bit like picking up a bottle of ketchup and finding the first two squeezes are barbecue and hot sauce samples when you just want to get at the tomato.
Consider that Microsoft and Google are no less eager to have you use their e-mail services and social networking features, they are rabidly interested in your business. They rely on your traffic and your browsing minutes to make money like any other comparable corporation.
Despite Yahoo! pushing it's services under your nose with every visit, take up of those services is dwindling and Google is gobbling up internet users at a staggering rate. With Bing, Microsoft is finally making inroads into the market; unsurprisingly with a minimal interface. Microsoft's search screen is much like Google's; they have chosen not to integrate it with the MSN portal which would have resulted in a cluttered mess much akin to Yahoo. Instead they adorn their page with only their search features and an image. It's less stark and it's clear to me why it's gaining in popularity.
The lesson is that we don't want to know about your pie-crimping and dog-waxing services. We come to search engines to get a view of all of our options from which we can explore and discover exactly what we want in our own way and at our own pace. The easier and more pleasant that experience is the more likely we are to return to you and if we feel assaulted by unwanted advertising and promotions we're not going to come back. This is true for any product that offers such a singular feature; the simpler and less-cluttered you make the user interface the better the experience will be for the customers you value so much.