As a few hundred Barcelona fans in a far-flung corner of the Santiago Bernabeu roared at the final whistle, millions around the world celebrated with the push of a finger. A little more than 2 million liked the club’s post on Instagram. Meanwhile 1.3 million watched the live video on Facebook. On Twitter, 886,000 tuned in for a six-second film of a changing room celebration, which then pulled another 2 million likes on Instagram. Barca’s 3-0 victory knocked Real Madrid out of the Copa del Rey on Wednesday. On Saturday, Barcelona have the chance to effectively eliminate their great rivals from title race too. This week’s Clasico double-header is not just being played out on the pitch but in clicks. “Football and social media make the perfect couple,” read a Real Madrid tweet last month. “Social networks have changed the way we enjoy the Clasico.” Real say their videos routinely reach more than 100 million views in the 10 days around a Clasico, more than the Superbowl in January, which hit 98 million. Spain is not the dominant country, with the United States just as engaged with Real, narrowly ahead of Mexico, Colombia, Peru, Brazil, France, Algeria and India. “For…