Akamai Technologies Inc., a Cambridge­ company that helps businesses deliver data more quickly over the Internet, had its biggest gain in six years as demand for cloud computing bolstered quarterly results. Profit excluding some costs was 43 cents a share. Analysts had estimated 37 cents. Sales of $331.3 million topped a $326.2 million prediction. “Even in tough economic times, companies are continuing their shift to do more business on the Internet,” Sagan said. “That’s Akamai’s sweet spot.”