While reading an article yesterday, I noticed a big error message where a Flash movie was supposed to appear. Basically, it said I should click there to upgrade to a new version of Flash. It even promised that I didn’t have to leave the page or restart my browser. But with all the viruses and spyware going around, I’m quite hesitant to click on this sort of thing. Making matters worse, there were obvious typos in the message, which made me even more suspicious about whether the message was legitimate.

I first saw spelling and grammar mentioned as ways to determine a document’s authenticity a few years back. This was around the time that those “Please verify your bank information” scams started making rounds. In response, the banks began telling customers to watch out for suspicious emails, and provided several tips to identify fraudulent messages. Among these telltale signs were a strange website address (i.e. not the bank’s website) and spelling and grammatical errors. The latter is especially interesting to me, as it arguably remains valid today.

When a piece of correspondence (email, website, ad, whatever) contains spelling errors and other mistakes, it makes the reader question the validity of it. I can’t think of the source right now (perhaps it was Steve Krug), but I once read a great study that showed how reader attention dwindled with each spelling error. Readers of an error-laden document went from highly engaged to barely even skimming the page, as the mistakes chipped away at their trust in the content.

With this in mind, my recommendation is to take the time to double-check all your correspondence. This is especially important for customer-facing documents like your website, although emails and other correspondence should be given some attention as well. Considering how few people actually do this, the benefits to those who take the time to proofread can be significant. All else equal, customers will place more trust in what you say and be more engaged by your message. You establish yourself as a person or organization that takes the time to make your words count. For at least some portion of your target customers, this will lead to more trust and increased sales.