The rise of mobile marketing has been long expected, and it looks like Black Friday 2015 is key milestone: mobile was more than half of web site traffic for e-commerce sites. Black Friday “brick-and-mortar” traffic was disappointing, but retailers were aggressively pushing sales online because it reduces the risks of riot-like runs for bargains as stores open. Target Stores had so much online traffic for CyberMonday its servers could not handle the volume. It wasn't the first time that Target misforecast demand for online sales. Some of Black Friday shopping may have been “window shopping” for mobile ordering. IBM, which still has a big business in systems for retailers issued a free download report about what was learned on Black Friday. In that report is the chart we highlight this week. If you sell to retailers or to businesses that sell to retailers, the report is worth reading.