Complex sentence: In the United States, the holiday season is a particularly important time for retail shopping, with shoppers spending more than $600 billion during the 2013 holiday season, averaging about $767 per person.
Split into simpler sentences: In the United States, the holiday season is a particularly important time for retail shopping. In fact, American shoppers have spent over $600 billion during the 2013 holiday season, averaging about $767 per person.