The sponsor gets publicity for their charitable donation—while the charity stimulates donations—by making donors feel as though they are getting better value for money.
If the sponsor proposes the deal, they can sometimes make the charity work harder at their fund-raising effort for the duration—which probably helps their cause.
If the charity proposes the deal, the sponsor can always pay the rest of their gift later.
The sponsor gets publicity for their charitable donation—while the charity stimulates donations—by making donors feel as though they are getting better value for money.
If the sponsor proposes the deal, they can sometimes make the charity work harder at their fund-raising effort for the duration—which probably helps their cause.
If the charity proposes the deal, the sponsor can always pay the rest of their gift later.