Interactive Democracy allows you to increase your political power in a number of ways: either become a member of parliament so that you can directly influence legislation and perhaps even become a member of the government; or persuade others, through argument and debate, to vote like you. The latter may involve you speaking at conferences, writing newsletters, blogging, campaigning on the high street or chatting with friends at the pub.
Liquid Democracy adds another way of increasing your voting power. It allows you to persuade others to link their vote to yours, automatically voting as you do. (They can rescind their link at any time.)