A new First Data Corp. (FDC) report based on all consumer spending activity over Thanksgiving and Black Friday shows e-commerce has grown steadily as a percentage of overall holiday sales. This year, the point-of-sales transaction processor says e-commerce represented almost 25% of all spending. The upward trend has accelerated significantly this year, with last year’s e-commerce as a share of total sales around 18%, compared to 15% in 2014 and 13.5% in 2013.

Credit and Debit Card Sales Up 9% From Last Year

These numbers are particularly important as a reflection of the U.S. economy at large, given retail remains a core segment, with a large percentage of retail sales occurring between Thanksgiving and Christmas.

After analyzing data from almost 1 million merchants, First Data concluded that sales are up 9% from a year prior. Sales of electronics and appliances gained 26.5% year-over-year (YOY), compared to the 2.3% YOY growth posted last year, while the average transaction grew over $41. The debit-card and credit-card transaction processor says its methodology is “based on actual consumer transactions rather than surveys or speculation.” First Data does not track cash purchases.

E-Commerce Boom Driven by Rise in Mobile Phone Use

As online purchases continue to grow as a percentage of total sales in the double digits, the 9% surge in Thanksgiving and Black Friday sales can be partly attributed to the rise of e-commerce. The near double in online sales as a percentage of overall sales was boosted by the growing use of mobile phones. Computer software company Adobe Systems Inc. (ADBE), analyzed data from 23 billion website visits, concluding mobile phones attributed to 36% of Black Friday’s online sales this year. Wal-Mart Stores Inc. (WMT) said 60% of its online orders on Black Friday came from mobile devices, up from 50% last year.

Adobe reported a continued surge of online spending into Cyber Monday, when e-commerce sales rose 12% YOY to $3.45 billion. (See also: First Data Partners with China’s Alipay.)