People think big companies use grammar well. Many people questioned Apple's grammar with its "Think Different" campaign in the 1990s. A study shows that big companies make grammar mistakes. The proofreading website Grammarly.com looked at the writing of six famous companies. They all made mistakes. It found that the companies who made the fewest mistakes made the most money. Grammarly compared different posts on the social network site LinkedIn.com. It looked at the spelling, grammar and punctuation mistakes in 400 words of text from each company.

Grammarly compared the mistakes from Coke and Pepsi, Facebook and Google, and Ford and General Motors (GM). Coke made four times fewer writing mistakes than Pepsi, and has a bigger share of the cola market. Google made nearly four times fewer mistakes than Facebook, and makes more money. Finally, GM made more mistakes than Ford. It is unlikely that grammar mistakes will make you buy a Coke instead of a Pepsi. However, Grammarly said: "Accurate writing demonstrates professionalism…and customers are more likely to buy [something] from a company they trust."