US retailer of action sports-related apparel, footwear, equipment and accessories Zumiez Inc., has posted total net sales of $31.5 million for the five-week period ended July 7, an increase of 48.8% compared with the $21.2 million reported for the five weeks ended July 1, 2006. Comparable store sales also improved, rising 13.7% versus an increase of 12.4% in the same prior-year period.