• GM and Facebook are in discussions to work together again, both companies have confirmed.
• Joel Ewanick, GM's CMO, dealt Facebook an embarrassing blow in the lead up to their IPO when he claimed the social network's ads were not effective.
• Ewanick and global sales head Carolyn Everson met for the first time since their meeting in Cannes.
• Everson said they will provide better metrics on ad effectiveness, but would not give special treatment for GM.
• GM has said it is not committed to a return until Facebook can prove its effectiveness.
   

From the article:

General Motors Co. and Facebook Inc. FB -1.05% are in talks to bring the auto maker back as a paid advertiser, two months after a high-profile falling out, people close to both companies said.

GM's global marketing chief, Joel Ewanick, dealt the social networking company an embarrassing blow when he said in May that paid ads on the website had little impact on consumers' car purchases. He said GM would stop placing paid ads there, days before Facebook's initial public offering.