He said he had received "encouraging responses from businesspeople looking to see where they can make a difference".
"It's encouraging to see business leaders also looking to see what they can do to improve the lives of children," he said.
"That speaks to the kind of people that we are and the kind of culture that we have. I'm really proud to be a New Zealander today."
He said he told the businesspeople that they could help by establishing relationships with local schools and social agencies to "partner with them in ways that make sense for them and make sense for you".
"You will make a difference," he said.
Public Health Association chief executive Warren Lindberg said his association would promote the #itsnotchoice message because it fits with the organisation's "values of reducing inequality and promoting good health for all".
"Let's be clear because the evidence is. The more unequal a society is, the less prosperous it will be as a whole," he said.
"We need to shake off the myth that the poor have chosen their lot and take immediate steps to stop the inter-generational slide into poverty that will only become even worse."
But former Green MP Sue Bradford, now with Auckland Action Against Poverty, said a hashtag campaign would not solve child poverty.
"It doesn't matter how many people take selfies of themselves with a cool slogan. Nothing will change until those in power take poverty seriously," she said.
She said an expert group appointed by Dr Wills came up with a long list of recommendations in 2012, but had been "almost completely ignored".
"The National Government and its supporters have a great deal of choice," she said.
"They could immediately do things like:
* Reform the welfare system so beneficiaries and their children are provided with enough income to cover adequate food, clothing and shelter.
* Accelerate the building and acquisition of state and community sector housing immediately.
* Commit to education, training and decent job creation for the unemployed who want and need jobs now, rather than using work-testing as a disentitlement tool against sole parents, the sick and the disabled.
* Ensure that all those who are without adequate or any housing have somewhere decent to live.
"Those choices do not lie in the hands of ordinary people struggling to survive."