Apple's iPhone 6 should mean a happy holiday season for one big-box electronics retailer, Piper Jaffray Senior Research Analyst Peter Keith said Wednesday.
Sales of the newest iPhone at Best Buy would be margin-diluted, he said. "But the kicker for Best Buy is that they get this fee from the carrier for signing up customers. So, they lose money on the hardware, but the sign-up fee, when you factor that in, it comes out about even with their corporate gross margin in the low 20s. If you can then sell an attachment, like a protective case where those margins can be 40, 50, 60 percent, then you're talking about a total basket that's accretive to margins."
On CNBC's "Fast Money," Keith said that he was originally expecting Best Buy same-store sales to rise between 1 percent and 2 percent in the third quarter, continuing into the fourth quarter.
Read More3 hot health-care stocks: Pro