AmEx’s new local offers pose threat to Groupon

American Express is releasing a new version of its iPhone app today that lets users find offers at nearby businesses. The new feature, dubbed “My Offers,” represents a threat to Groupon, which has tried to entice merchants to market through its mobile product, Groupon Now. (Full disclosure: I have a very small stake in AmEx and a variety of short positions in Groupon.)

11 productivity tips from successful entrepreneurs

When everything’s a priority, how do you maximize your productivity and continue getting things done? We asked eleven entrepreneurs about their strategies for staying on top of mounting piles of work, focusing on what’s important, and otherwise holding on to their sanity while building a company.

Why your startup’s culture shouldn’t be ignored

Starting a new technology company is exciting. Since the founders have their energies fully focused on new technologies and innovations that promise to change the world, there is little time left for them to think about creating the right culture for the company. Hence, more often than not, the company’s culture takes after the styles and personalities of the founders. (Above, CollegeHumor’s startup guys.)

Study: Groupon’s merchant quality is on the downslide

Have you had the feeling the quality of Groupon deals is going down? If so, you’re right. A report released this morning by Giorgos Zervas, a postdoctoral fellow of computer science at Yale University, shows that the average rating of a Groupon merchant before a deal runs is declining as Groupon matures. Zervas and other researchers had shown earlier that a business’s individual Yelp ratings dropped after running a Groupon. Yelp ratings by Groupon customers were, on average, 10% lower than those of their peers. (Disclosure: I met Zervas after the initial study and offered my theory that the average Yelp rating of merchants featured would be declining.)

7 ways BYOD will boost your business

If you haven’t already heard of the bring-your-own-device trend, then get ready, because you’re going to be hearing more and more about it over the coming year. What’s more, this trend isn’t just a matter of employees wanting to use their own tablets and smartphones at work; they want to bring the social apps they’re familiar with into the enterprise too.