According to ComScore, Inc 28% of US shoppers say social media has influenced their holiday purchases this year.

Here's how it breaks down.
Of the types of specific social media that consumers say influenced holiday purchases, the most common were:
- Reading a consumer-generated product review (13% of respondents)
- Reading an expert product review (11%)
- Following a fan page on Facebook to take advantage of special offers and deals (7%)
- Influence by a friend’s Facebook status update referring to a particular product (6%)
- Following a company on Twitter to take advantage of special offers and deals (5%)
- A friend’s “tweet” about a product influenced their purchase behavior (3%)
Source