Sophisticated donors hopefully know to ignore "matching" pitches (but if not, it's certainly helpful to spread awareness that it's basically just a marketing gimmick).

But my sense is that relatively few people are sophisticated donors who could accurately be described as "allocating their charity budget". Rather, I model most people's philanthropic motivations as unstable impulses that come and go as emotions hit them. Marketing gimmicks can be very helpful for exciting such donors, and motivating them to do something good rather than nothing.

If anything like my model is accurate, then asking effective charities to forego marketing gimmicks seems like a bad idea. It just means that the unstable impulses of the hoi polloi will be exclusively activated by less-effective charities that have no such anti-marketing scruples.

(If we could secure a world where no-one engaged in marketing gimmicks, that would indeed be preferable. But I take it that we can't secure such an outcome. All we could achieve is unilateral disarmament, which makes things overall worse, not better.)

Relatedly, when I worked in ad agencies I'd always tell my clients to avoid putting their products on discount. The research I've read shows they:

1. don't impact long term sales

2. tend to just attract people who would've bought anyway (but at a lower price)

3. get people used to buying at a lower price

"a brand's normal-price buyers are a major source of its volume from price promotions" https://www.researchgate.net/publication/321247500_Buying_Brands_at_Both_Regular_Price_and_on_Promotion_over_Time

I think matching could be like discounts / price promotions (i'd guess at ~ 50% this is happening); you're just moving money around different timelines and having other negative effectives on your brand.