Gravitytank, a Chicago innovation consultancy that helps brands grow their businesses, has been acquired by Salesforce. Gravitytank announced the news Tuesday in a blog post, and said it will combine its "expertise in design, research and strategy to help Salesforce's customers shape their customer company vision and connect with their customers, employees and partners in new ways." Founded in 1999, Gravitytank works with brands across a range of industries, including consumer electronics, consumer...