But mothers still rule with a 5% higher average order.

U.S. retail online sales for the week leading up to Father’s Day were up more than 14% compared with the same period last year. Department store online sales grew by 30.5% over the same period last year, with mobile sales in that merchandise category growing by 29% year over year, according to IBM’s Digital Analytics Benchmark research.

Father’s Day week online sales for home goods grew by 21.4% compared with the same period last year, and mobile sales for home goods increased by 25%, the IBM study says. Father’s Day web-based apparel sales grew by 13.5% and mobile sales grew by more than 42% year over year, says IBM’s study, which is based on a web-based digital analytics platform that tracks millions of transactions from approximately 800 retail sites nationwide, the company says.

Following is a summary of additional findings from the study conducted from June 9-June 15, the week leading up to Father’s Day 2014:

  • The average order value for Mother’s Day online spending in 2014 was $125.23, 5% higher than Father’s Day average order value of $119.37.
  • Mobile traffic accounted for more than 38% of all online traffic, and was 26% higher than the same period last year. Mobile sales saw strong growth, up more than 37%, reaching nearly 19% of all online sales.
  • Smartphones drove 24.8% of all online traffic and tablets 12.8. But when it comes to making the sale, tablets drove 12.2% of all online sales while smartphones accounted for nearly half of that at 6.4%. Tablet users averaged $106.71 per order, versus smartphone users, who averaged $89.55 per order.
  • As a percentage of total online sales, devices using Apple Inc.’s iOS software account for almost 4.5 times more sales than Android phones and tablets, driving 15.2% of web sales vs. 3.4% for Android. On average, iOS users spent $103.85 per order compared to $73.08 for Android users.
  • Shoppers referred from Facebook averaged $99.43 per order, compared with Pinterest referrals, which drove $142.75 per order. But Facebook referrals converted sales at a rate more than four times that of Pinterest referrals, possibly indicating stronger confidence in recommendations from the more established social network, the study says.