Most of the young voters would be first time voters; possibly without committed ideological loyalties to any particular party. Therefore, the returns to an online campaign might be higher. Also, in constituencies where the margin of victory was low, the young first time voter could be the marginal voter (if most of the repeat voters have loyalties and there is no clear cut anti incumbency wave, the winners could be decided by the way these voters cast their vote).

The cost of an online campaign is lower than that of a physical, door to door campaign. Also, it is mostly a fixed cost with incremental updates to websites or generation of messages done by free volunteers. This could increase its attractiveness.

There is also a Prisoners Dilemma at work here. If no other party uses the internet, I am better of using it; If every other party uses it, I need to use it to avoid losing out. End result – Everyone would use it and possibly no one will benefit unless somebody’s campaign is clearly better.