A couple of months ago, I asked my mailing list (sign up here!) all to participate in a short survey. I got a handful of responses (about 20 or so) and the results are clear: yes, bad spelling and grammar turns customers off.
Responding to When you see a business with spelling or grammar errors in their marketing or advertising, what is your perception of that business?, four-fifths said it looks "sloppy."
Most (80%) agreed that "Better spelling and grammar means better attention to detail."
Almost all said if they saw a spelling error in a piece of their communications, they'd rewrite it. (One person said they'd ignore it. I can't wrap my head around that. At all.)
When asked How much do you agree with the following statement: "Writing that is simple and direct is easier to understand" all respondents "strongly agreed" (an 8/10 or more.)
Here's the big takeaway: not ONE response went above neutral when asked "if you see a business with spelling or grammar errors in their marketing or advertising, does it make you more or less likely to buy from them?" It generated an average of 3/10 - meaning "extremely unlikely."
If you think that bad spelling or grammar doesn't effect your business: it's time to think again.
My lame superpower is finding spelling and grammar errors in writing - but as lame as it sounds, it could help your business win more customers with a polished presentation.