Facebook and General Motors may be rekindling their advertising relationship after publically bickering in the past few months.

According to reports from the Wall Street Journal, the two companies have been in discussion about brining GM back into Facebook's advertising platform. Facebook is said to be providing GM with helpful information on how the company can increase its ad effectiveness.

GM upset Facebook in May when it took its $10 million ad campaign from Facebook, explaining that the company's ad spending did not reflect in increased sales.

A source told CNET afterwards that an announcement was made saying "Facebook advised [GM] to invest more wisely in a campaign that would reach more people," but GM did not do so.

Although Facebook has tried to get GM to return its ads to the site, GM has made no official agreement to do so. Predictions are that GM is waiting for Facebook to prove that the investment will lead to profits, before the company decides to come to an agreement with Facebook again.

Despite Facebook's claims of increasing companies' sales through advertising on their page, a recent U.K. study from digital-marketing agency, Greenlight, found that 44 percent of respondents admit to "never" clicking on an ad listed on Facebook.  Thirty-one percent said they "rarely" click on ads and only 13 percent said they either "often" or "regularly" click on ads.