CBS announced this week that the 28th season of “The Amazing Race” would feature social-media stars from Instagram, Vine, YouTube and podcasts. While the number of online followers for each contestant varies, they are responsible for a combined 72 million hits on social platforms. According to The Wall Street Journal, “the choice by ‘The Amazing Race’ producers to seek contestants with large followings online reflects the growing importance of social media: It’s no longer a back door to stardom, but a necessary tool to land a first interview. It’s also the latest example of how tech culture is spreading.”