Perceptions matter a lot. Before 2014 elections, a question was constantly asked on social media by many people as to what Congress did for 60 years, a question originally floated by BJP. Though the question itself is ridiculous, but since it went unanswered for the most part, it became part of the psyche of many - Congress did nothing for 60 years.
Social Media has been around for well over 10 years. Congress President Sonia Gandhi doesn't have any social media accounts while Congress Vice President Rahul Gandhi made one only in 2014. Most senior Congress leaders, with the exception of Shashi Tharoor, joined social media just a few months before the elections.
Even the main Twitter account of India's 'oldest political party' had far less number of followers than the Aam Aadmi Party Twitter account which had been in politics only for 3 years at that point of time.
Even if Congress wished to communicate, it did not have the means to reach the huge middle class population which increasingly relies on social media and online media for news/information rather than news papers. Their spectacular failure at realizing the importance of social media and communication was one of the many reasons why they were reduced to 44.
In comparison, BJP has a social media reach that is unprecedented. Just their WhatsApp network is so enormous that even the smallest rumour/achievement is broadcasted across the breadth of the country in no time. While Congress leaders continue to be dormant on social media for the most part, BJP leaders are ultra-active.
Every small achievement including the electrification of a single village anywhere in India is broadcasted as an achievement and distributed across their network. While over 90% of the electrification of about 6 lakh inhabited villages across India happened before the Modi government, what people would remember is the 10,000 odd villages that were electrified since BJP came into power.
Such is the power of communication and BJP and Modi have mastered it like none other.