The deal includes a provision that will allow the Giants to buy an additional 30 percent of the team -- which would constitute a controlling interest -- in 2010.
San Jose team president Jim Weyermann began seeking a partnership with the Giants in 2005, initiated by a conversation between Weyermann and San Francisco vice president of player personnel Bobby Evans.
"But it got serious during the [California League] Championship Series in 2007 in Lake Elsinore," Weyermann told MiLB.com. "The discussion really gathered momentum during the 2008 season. And as talks went on we explored what made sense, how we could strengthen our presence here and how the Giants could expand their brand."
For the San Jose team, the need for corporate partnership seemed clear, and the Giants were the ideal partner for obvious reasons.
"When you're playing in a building built in 1942, and not very many of us are...," explained Weyermann, "When you have five showerheads and two toilets for 40 players, you have to ask yourself, 'Is that the kind of experience you want your No. 1 Draft picks to have?'
"We had some real facilities issues here. We needed some major improvements. We've made some major improvements, and this deal is going to allow us to make a lot more."
The proposed purchase gained wide support in the Giants organization when Bill Neukom was named managing general partner in the fall, according to Weyermann.
"His wanting to firm up the farm system and focus on player development was a big help."
In addition to stadium renovations and a better player experience, Weyermann knew revenue would have to increase if the Class A Advanced squad was to continue to thrive in San Jose.
"Look at this market. We have the Giants and the A's. Don't forget we also have 12 Division I schools. We have the 49ers. We have the Raiders. We're not big fish in a small pond. We're swimming with sharks. To compete in this huge market, we needed the leverage of a corporate partner."
Now that the Minor League team has found that partner, local fans should recognize changes for the better immediately, including the possibility of San Jose Giants games airing on Bay Area cable television.
"For San Jose Giants fans, there are going to be huge benefits. Just look at Opening Day, when we're going to have five of the top six prospects in the Giants system on our team," said Weyermann.
"[With this deal] you're talking about bringing FanFest to Municipal Stadium. We can connect with community funds -- youth sports outreach on our end and breast cancer awareness on theirs. The fans will see the benefits of this deal on the field, through the experience at the stadium and on their TVs through broadcasts of San Jose Giants games."
The Oakland A's are actively seeking to build a new home in the Bay Area. After the possibility of relocation to nearby Fremont was nixed in February, talks involving San Jose heated up. On Monday, Major League Baseball commissioner Bud Selig appointed a committee to investigate options for the Athletics, including those in the San Jose area.
But San Jose team officials insist the Giants' partial purchase should not be seen as a calculated maneuver to thwart the Oakland organization.
"What people who aren't in San Jose day in and day out don't understand is that the A's conversation has been going on since 2005. To say this is a direct response to that is totally ridiculous," Weyermann said.
"There has always been talk about the A's moving in to San Jose. Even when the A's talked about concentrating entirely on Fremont, people were still talking about them coming to San Jose -- reporters were still speculating they wanted to come here. That conversation has been ongoing for three or four years."
Weyermann added, "But we're here until we're not. We've been operating on a business-as-usual basis here. If we weren't, we wouldn't have set back-to-back-to-back attendance records.
"For us, this partnership just makes sense."
Josh Jackson is a contributor to MLB.com. This story was not subject to the approval of the National Association of Professional Baseball Leagues or its clubs.