"I've heard a lot of talk about wages and demands and all that I can honestly say is I don't pay football for money," said Bullard, 30, who has agreed a four-and-a-half year deal at the KC Stadium.
"I've come up to Hull because they are ambitious and because I want to play for a club who wants me. Simple as that.
"I've never been interested in money as such. So it's sheer football reasons. I wasn't asking for anything. I was in contract talks and the talks went as far as 'we are not going to offer you any sort of contract'.
"I left saying I wanted to play for a club who wants me. It was agreed like that. It was a weird discussion I had. When I came up here and I knew that Hull wanted me it was made easier for me."
Bullard, who still had 18 months of his Fulham contract to run, was told in November that he could leave in the January transfer window.
Hull chairman Paul Duffen hailed him as "one of the top three midfielders in the country".
Hull manager Phil Brown, meanwhile, praised Bullard "impish, boyish attitude" and for playing the game with a smile on his face.
Bullard, who is not Cup tied, missed the FA Cup tie with Millwall with a stomach bug but will be fit to make his debut at West Ham - the club who released him as a youngster - in the Premier League on Wednesday.