To pretend they are doing something good or helpful to the community.
( because they just got tax exempt status for being a religion)
And they will use this opportunity to try to recruit more people into their evil cult.
Try and connect with people donating, make them think they are good people who have been mislabled, while using modern pop culture to make themselves( the satanic temple) seem cool. When they have celebrities embracing their evil culture, they can use that to recruit more.Like Chelsea Clinton and Chrissy teigen having twitter fun with the satanic temple, making it appear harmless, funny, cool, etc.
I use the word cool, to describe making it look appealing to young people. Like teens smoking in films during the 70's/ 80's/90's.
They probably keep a portion of the blood donated to them, for their sick rituals, or to drink or for some other fucked up reason, kek