One of Australia's biggest online petition providers, Change.org, announced it now has 3 million active users across the country, which means one in seven Australians has started or signed an online petition.

"Usually [users are] frustrated or impatient with politicians, or want an effective, uplifting way of winning a David vs Goliath battle and play a profound part in creating meaningful social change. A petition wins on average at least every day," a Change.org spokesman said.

But as they become more common, experts believe their power is being diminished, as important social and political issues get overshadowed by trivial topics.

Jill Sheppard, who specialises in internet politics and e-participation at the Australian National University, said there were more petitions than ever being sent to policymakers with a decreasing attention span.

"The popularity of online petitions has absolutely diluted their power to actually achieve change. Parliamentarians are receiving more and more appeals, without seeing any associated increase in people's obvious concern," she says.

It's incredibly easy for people to add their name to an online form, Dr Sheppard says,  and policy-makers know this.

"The more effort citizens put into their lobbying activities, the more likely the targets are to listen and act."

Change.org and Getup.org, which is more politically motivated, are the biggest providers of online petitions in Australia. They market themselves as giving a voice to people and groups who feel disenfranchised and in need of justice. Indeed, there have been some significant success stories in which online petitions at least  helped bring about change.

But for every success story, there are many petitions that fail to gain support, and plenty that are concerned with less-than-serious topics.

One current petition is to pressure Today show host Karl Stefanovic to appear at a Melbourne bar to perform a DJ set. And four years ago, a user created an online petition asking for people to stop supporting online petitions. It attracted six supporters.

Last year, researchers from Oxford University and University College London  studied the number of signatures across online petitions on the British Parliament e-petition website and found that people were more inclined to sign if the topic was "trending" or already popular.

This was "at the expense of those with less signatories".

Dr Sheppard says petitions,  online and old-fashioned pen on paper, have had "enormous success" throughout history. She highlights the 2012 online campaign for advertisers to boycott shock jock Alan Jones' 2GB radio show after he said then-prime minister Julia Gillard's father had "died of shame".

The campaign worked, with Coles, Woolworths, Dilmah, ING Direct, Freedom Furniture, Lite 'n' Easy. Mercedes-Benz and more either ending or suspending advertising on Jones' show.

"But three years on, and Alan Jones is as popular as before. The station did take a financial hit but the effects have dissipated over the longer term."

This is because online petitions are easy to organise and support, but there are still times when they can make a difference, she says.

"Obviously at the top end, tens or hundreds of thousands of petition signatories can still result in change, whether signed online or offline."