Fundraisers need to stop using terms such as "mass acquisition" because they risk alienating people, according to Kath Abrahams, director of engagement and fundraising at Diabetes UK.
She said the sector needed to focus on developing meaningful relationships with supporters as well as making fundraising asks.
"We have to move away from terms such as ‘mass acquisition’, even as shorthand, because phrases like that are one of the things that make people think they’re just numbers to us," she said.
For Diabetes UK, she said, the focus was on "engaging people in meaningful relationships, over time".
She said: "Part of that relationship, we are absolutely clear, is an unashamed request to people that they support us financially because we can’t do any of the work we do without their help."
However, the relationship was also about showing supporters what the charity did and helping them to understand the problem it was tackling and the solutions it offered, she said.
This often led supporters to want to support the charity financially, Abrahams added.
Sam Butler, director of fundraising and communications at the Tibet Relief Fund, agreed.
He compared the situation in donor acquisition over the past 10 or 15 years to having a hole in the bottom of the bath you were trying to fill.
"It got to the point where the amount you were spending to top the bath up was more than you were going to make in three or five years to pay back that initial investment," he said.
Butler added that the 2015 fundraising scandals had led charities to begin focusing on stewardship and there was evidence charities could still achieve growth by focusing on the quality rather than the quantity of donors.