Groupon will reportedly hire up to 100 engineers for its Palo Alto office, adding to the 200 people already there. For the most part, those in place are data analysts, technologists and developers who focus on mobile and merchant products. Business Insider says the company plans a recruiting event in the area later this spring, and is already buying billboard space along the area's highways.

The office works mostly on mobile and merchant products, including some apps for Groupon Merchants like one that allows merchants to scan groupons with their iPhones. The Groupon Scheduler also came out of the Palo Alto office. Because Groupon has grown the office's headcount mostly through acquisition, about one-in-three employees out there are former CEOs or startup entrepreneurs.