eBay reported that holiday volume on its iPhone and other mobile phone applications tripled compared to last year, with 1.5 million items purchased worldwide. Nearly 6 million people are carrying access to eBay on their smart phones. Purchasing items on the go is a trend that analysts say can only increase. According to one report, mobile Internet users will double by 2013 to surpass 1 billion.

Snowstorms this past weekend helped boost online sales 13 percent over the pre-Christmas weekend last year, and the holiday season to date has seen a 4 percent increase, according to an update today on Internet purchases by comScore. The final shopping weekend of the season (Dec. 19-20) had a strong 13 percent growth rate, with reported online sales of $767 million, as snowstorms on the eastern seaboard prompted “many consumers to finish their holiday shopping from the confines of their own homes,” reported Virginia-based comScore, a provider of “digital marketing” intelligence.

Combine the Twitter concept with your credit card purchasing habits and you get Blippy, a new social media site in beta testing now and launching next year that lets your friends – or anybody – keep track of what you’ve bought with plastic. Blippy’s founder is Internet entrepreneur Philip Kaplan, the former chief executive at AdBrite, which places ads on more than 100,000 affiliated sites and had 2008 revenue of $31.6 million.

Less than one-third of Christmas shoppers surveyed said they used credit cards as their preferred payment method so far this holiday season, according to a new survey by the National Retail Federation. Nearly four out of ten (39.3 percent) have used their debit or check cards most often. Fewer people have used credit cards as their preferred payment method this year – 30.9 percent, compared to 33.8 percent in 2008. More than one-quarter have used cash, and a mere 3.8 percent have relied on checks.

Cyber Monday was a success for online retailers with an 8 percent increase in visitor traffic over last year, according to the National Retail Federation, the largest retail trade group. For credit card issuers in particular, the initial online figures are encouraging. However, online shopping represents less than 10 percent of all Christmas holiday season spending.

While initial figures showed flat numbers for store sales on Black Friday, the average that online shoppers spent surged an impressive 35 percent compared to last year, according to an analysis of Internet spending. Coremetrics, a San Mateo, Calif.-based Web marketing data firm, also found that consumers are spending considerably less time browsing retailers’ sites. Its analysis suggests that they “had done their research prior to Black Friday and that they are shopping from lists.”