I wonder what is the salary of the executives.
Wonder no more, they have it in their 2022 tax filing:
Compensation
Key Employees and Officers Base Related Other
Jim O'leary (Vp, Engineering) $666,909 $0 $33,343
Ehren Kret (Chief Technology Officer) $665,909 $0 $8,557
Aruna Harder (Chief Operating Officer) $444,606 $0 $20,500
Graeme Connell (Software Developer) $444,606 $0 $35,208
Greyson Parrelli (Software Developer) $422,972 $0 $35,668
Jonathan Chambers (Software Developer) $420,595 $0 $28,346
Meredith Whittaker (Director / Pres Of Signal Messenger) $191,229 $0 $6,032
Moxie Marlinspike (Dir / Ceo Of Sig Msgr Through 2/2022) $80,567 $0 $1,104
Brian Acton (Pres/Sec/Tr/Ceo Sig Msgr As Of 2/2022) $0 $0 $0
from https://projects.propublica.org/nonprofits/organizations/824506840
"As of January 2022, the platform had approximately 40 million monthly active users."[0]
In 2022 they had $30M expenses, so the cost is somewhat under $1/user/year.
They said the minimum donation is there to reduce the viability of scammers using it to check if a stolen credit card number is valid.
[0] https://en.wikipedia.org/wiki/Signal_Foundation