As the party conference season kicks off amid fears about dwindling party memberships, NationBuilder’s Jim Gilliam pointed to the need for activists to be further empowered with messaging.
He said: "The real opportunity that this presents to parties is to give up centralised control and lead with values first to help people craft their stories."
NationBuilder's suite of online campaign tools is being demonstrated to Liberal Democrat members at their conference tomorrow.
Tim Snowball, the Liberal Democrats' director of comms, has praised it as "an important digital tool" for the 2015 election.
It was also adopted by Labour earlier this year, while the Tories are understood to be looking at the technology.
Pointing to the success of the Obama re-election campaign, much of which used the power of the internet, Gilliam warned of a need to loosen central control over the party message.
"In the States, we’ve seen you don’t need the party’s permission to run a great campaign, and campaigns can actually be better as they are uninhibited by what the party wants to do.
"With the message discipline you see in terms of getting everyone to say the same thing, it is not authentic and it doesn’t connect.
"This presents an opportunity to go in the opposite direction, with people speaking in a genuine way, inspiring them to join up and volunteer."
NationBuilder was founded by Gilliam three years ago, has 60 staff, and its customers have collectively raised more than $110million (£69.5m) using it.
It was used on the Liberal Democrats amillionjobs.org campaign, and Labour’s Movement for Change, which in two years has trained 2,500 people face-to-face as community organisers.
Efforts to re-engage activists come in the context of declining party membership. In 1953, the Tories had 2.8 million members, while the Labour party had a million. Last December, it was estimated this has dropped to 170,000 and 193,000 respectively.
For Gilliam, maintaining the connection between off- and online work is crucial to re-engaging both voters and die-hard activists.
"The key point is to get everyone sharing their own story. This method of organisation is very old, but doing it online is very new. Once you can use the technology, it's all about linking that through to your activities and using it to get people knocking on doors and hosting fundraisers."
Political parties that did not answer the call to devolve their messaging and empower their members risked their future, he added.
"Parties here will have to lead the charge if they want to stay relevant."