Billionaire entrepreneur Mark Cuban says he has invested in Thinking Voice, a maker of click-to-call internet links for emails, e-commerce websites, social networks and other internet venues, reports CNET. The infusion will help Thinking Voice launch CallActivator, which sets up phone calls with a click of a web link, the company announced on Wednesday. The technology is at the heart of the company's new e-commerce network, which pays website operators based on the amount of sales leads they generate rather than on click-throughs or actual product sales.