Trendy footwear company Skechers USA Inc on Thursday revealed it swung to a second quarter loss as its performance was hampered by higher advertising costs and falling sales amid tough trading conditions. The California-based company reported a net loss of $2.1 million, or six cents per share, versus a year-ago profit of $21.3m, or 52 cents a share, in the year-ago period as sales for the 13 weeks to June 30 slumped to $229.3m from $256.7m.