Amazon, the golden child in an industry full of retailers duking it out for single-digit comparable sales growth, raised eyebrows with its disappointing sales guidance for the holiday season.

The online giant is in many ways facing a different environment than it did last Christmas, as bricks-and-mortar stores continue to evolve their Web capabilities and chip away at Amazon's price advantage. Along with stiffer competition, Amazon is also vulnerable to the hesitant consumer who, despite a slew of economic tailwinds, is still reluctant to spend.