A long time coming, the combined efforts of major players and successful startups have irrevocably changed the way consumers shop.

In the tech world, 2010 will be remembered for a few newsworthy events. The iPad launched last spring and took tablets mainstream. In August, sales of Android devices trumped iPhone sales for the first time. And just several weeks ago, the industry eagerly witnessed Google's (GOOG) jaw-dropping (and rejected) bid for Groupon.

Behind the scenes, a much more subtle, but no less important, transformation took place. This year, more than ever, American consumers changed the way they shopped thanks in large part to web sites and apps that reshaped the discovery process with more tempting online offers, easier ways to compare prices, and innovative solutions for attracting customers to stores.

So far this holiday season, consumers have spent $27.5 billion online, a 12% increase over last year, compared with overall retail growth, which grew just 3 to 4%. And according to the National Retail Federation, e-commerce sales on Black Friday jumped 15% to make up 34% of all shopping that day. Meanwhile, daily deals sites like Groupon and LivingSocial are reporting banner years, and recently-introduced mobile apps like ShopKick claim rapid adoption, both from consumers and retailers.

Long gone are the days when consumers merely crawled through newspaper ads and trekked out to brick and mortar stores. Through the power of the web, the smartphone and the tablet, they have more options than ever. More