The report was based on an analysis of 250,000 campaigns sent by brands in 2016. The researchers passed the messages through an automated grammar and sentiment checking tool to measure how error rates and tone change over the course of the week.
Campaigns sent on Mondays have the most errors (spelling mistakes, grammatical issues, improper capitalization, etc.) in subject lines, on average.
Emails sent on Fridays have the second-most errors in subject lines, on average.
And emails with mistakes in their subject lines have a 14% lower average response rate than emails that don't have mistakes, the analysis found.
Emails sent on Mondays also have the least positive subject lines, on average.
Campaigns sent over the weekend have the most positive subject lines, on average.
Ayaz Nanji is an independent digital strategist and a co-founder of ICW Content, a marketing agency specializing in content creation for brands and businesses. He is also a research writer for MarketingProfs. He has worked for Google/YouTube, the Travel Channel, AOL, and the New York Times.
LinkedIn: Ayaz Nanji