When they send me a request saying that someone is willing to match so that the charity will receive double the amount I give, I generally will donate.
At the company I worked for before I retired, they would match donations to a particular decent charity on Giving Day, and on another day they would double match. They were in general an annoyingly cheap company that wouldn't match our 401k contributions (originally no match at all, they later matched a little bit), so in the spirit of revenge I donated to the charity the maximum amount that our cheapo company would match. I don't know if the other employees were also motivated by revenge or perhaps just very generous, but we all donated so much that our company maxed out the amount they had been willing to give, and they had to convene a board meeting to decide to up their amount more since their employees had been so generous. Ha, guess we fooled them!