Macmillan Cancer Support's tie-up with npower is worth more than £1m.
According to research by nfpSynergy, the partnership between Macmillan Cancer Support and energy company npower is among the most recognised corporate-charity tie-ups in the country.
And the contribution of the cancer charity to boosting npower's relatively young brand - the firm is only five years old - is foremost in the minds of executives at the company, which recently lost the endorsement of Greenpeace for its green energy tariff, Juice.
Rose Gardner, community investment manager at npower, says supporting Macmillan has brought depth to the company's business, strengthened the brand and increased trust. "If somebody trusts you they are more likely to buy from you," she says. "The Macmillan partnership is part of building that trust among potential customers.
"I get frustrated with the common misconception that community investment is essentially companies giving away chunks of money in order to tick fluffy PR boxes."
Npower also credits the partnership with helping to recruit graduates and swelling staff morale, while Macmillan values the partnership, which has been running since it displaced ChildLine as npower's 'corporate charity' in 2004, at more than £1m.
The firm kickstarted proceedings with a £200,000 donation and gave another £100,000 last year. It also matches donations by its employees, doubling the £50,000 raised for the World's Biggest Coffee Morning for the past two years.
Diana Edmunds, account manager at Macmillan, says the relationship with npower is one of the charity's most dynamic partnerships.
"Virtually every department has some contact with npower," she says. "We support its staff in their fundraising efforts and look at new ways of getting brand exposure - not just for npower, but also for Macmillan."