Massa insists he will remain a "professional" racing driver in his own right at Williams.
Nov.21 (GMM) Felipe Massa has likened Formula One pay-drivers to prostitutes.
After eight years with Ferrari, the Brazilian will switch to Williams after this weekend's 2013 season finale in his native Sao Paulo.
It was thought that Massa, 32, was bringing some Brazilian sponsorship backing to the seat currently occupied by the heavily PDVSA-backed Pastor Maldonado.
But Massa insists he will remain a "professional" racing driver in his own right at Williams.
"For all that I've gone through, and everything I've achieved, it makes no sense to pay to race," he is quoted by Brazil's Globo.
However, Massa said he would help Williams - the once-great F1 team - to find some new sponsors.
"Of course, I will do all I can," he said. "Money is good for improving the car and I have great relationships with some companies, some of them Brazilian.
"The crisis has hit all teams, big and small," added Massa.
He said he also negotiated with "Lotus, Force India and McLaren" about 2014.
"But (Lotus team boss Eric) Boullier did not do anything as though he really wanted to do something (for 2014).
"Then Williams came after me. The first conversation was 'We want you'. And that was very important for me."
Massa said he was not interested in becoming a 'pay driver', in the sense that a driver's services are inextricably linked to his financial backing.
"I don't know if this is how I should describe it, because it is a very strong word," Massa said.
"But the word is 'prostitute'," he is quoted by UOL Esporte. "Not having to do that - pay to drive - is my greatest pride.
"It is logical to help with sponsors, but I will not be a prostitute," added Massa.