Just to add to this. Shoprunner membership is free for 30 days, but $8.95 /month or $79/year for membership after the 30 days are up. Please correct me if I'm wrong on this.
Also, shipping to store apparently is not free for orders under $50, so S/H is not free. Total cost is ~ $27 if you can't get the free shipping.
Many people on SD got in on the "year for free" which has been offered a few times. They have even extended that offer to 3 more month or even another year. I am going on my 3rd free year, I think.