Consumer New Zealand says there has been huge demand for its 'Do Not Knock' stickers with almost 100,000 already handed out.
The campaign was launched earlier this month in response to complaints about aggressive and exploitative door-to-door sales tactics.
Consumer New Zealand chief executive officer Sue Chetwin said another 50,000 stickers had been ordered.
However, she said stickers could only do so much and what was needed is tougher rules.
Executive director of the Direct Selling Association Garth Wyllie said while his groups supported the campaign, the stickers would not put some salespeople off.
"Unfortunately you're always going to have some, what we call 'rouge traders' and these are the guys that will push the hard sell at the door and not take no for an answer."
Mr Wyllie said the stickers would not hold much legal power to stop salespeople door-knocking.
Ms Chetwin said in Australia, it was a fair-trading offence to ignore a do-not-knock sign, and she planned to approach the Government about adopting the same system in New Zealand.