One element that seemed to help differentiate the Giants from the A's, who he started his career with, was their ballparks.
Often mentioned among the top baseball stadiums in the country, AT&T Park is a gem and a card the Giants can play to attract free agents. Meanwhile, the A's have O.co Coliseum's sewage problem as a hurdle.
In Hudson's case, it was a factor.
"It's a place a lot of opponents envy, the atmosphere and the way the fans support the team...It was a pretty easy decision when it comes down to the nuts and bolts," Hudson said. "It's hard to say there was a close two or three."
A similar feeling appears to have helped the Giants retain Javier Lopez, one of the best left-handed relievers in the game.
"Winning two World Series here and playing in front of sellout crowds every day, that's what every player strives to do, and I have that here," Lopez told CSN Bay Area's Andrew Baggarly in September.
Even in a year the Giants just finished a disappointing 76-86, the team still ranked No. 3 in attendance with 3.3 million fans, according to ESPN.com.
In addition to the nightly crowds of 40,000-plus, the park's dimensions also make it attractive to pitchers. It ranked as baseball's fourth-best pitcher-friendly park last season, according to ESPN.com's MLB Park Factor.
The MLB Park Factor also indicates AT&T Park averaged just 0.768 home runs per game -- the third-lowest in baseball. Home runs elsewhere can turn into long outs at AT&T, especially in right-center where "Triples Alley" measures 421 feet.
The ballpark isn't the only reason why free-agents pitchers want to come to San Francisco.
Free agent Bronson Arroyo, who was 14-12 with a 3.79 ERA last year for the Reds, is intrigued by playing for the Giants.
"I love San Francisco, " the pitcher told USA Today. "I love the whole vibe of the city. I love walking down the street and see a guy in a tuxedo, two guys holding hands and some girl with tattoos riding a skateboard. I love the eclecticness of the city."