My journalism professor had an interesting grading philosophy: for every factual error in your paper, you lost 35% of your mark. But for every spelling mistake, you lost 50%. That’s right: if you spelled something wrong, you automatically failed.

Initially, I felt this was a highly flawed strategy – how could a spelling mistake be worse than a factual error? His argument was that although a factual error was terrible, it could be corrected. A spelling mistake, on the other hand, jeopardized your credibility.

Understand that this was in a slightly more idealistic time, and long before the proliferation of fake news and alternative facts. So I’m certain if he was still teaching today, his grading system probably would have judged both crimes much more equally. But regardless, his point still resonates: the proof is in the proofreading.

Now, I’m far from a grammar geek, and I am certainly not immune to “auto-cowrecks” in daily correspondence. But when you’re sharing your insights on a blog post or a white paper, the most compelling argument can be undermined by a simple spelling mistake.

There are plenty of tools that mitigate the risk of typos. Grammarly is one application I use that acts as a real-time, virtual proofreader across all applications, including online forms and social media platforms. Going beyond a standard spell check, the Grammarly editor can detect when you’ve inadvertently missed or misused a word. This can be highly useful to ensure you don’t publish a typo in your Facebook feed or email.

But no technology is a match for a real proofreader: someone who actually reads your words with fresh eyes and ensures that what you’re writing is what you intended. (Everyone wave to Carmen!)

Proofreaders are unsung heroes who save us from ourselves. They work on a word-by-word basis to eliminate errors and inconsistencies in spelling, punctuation, grammar, formatting, and presentation of numbers and capitalization based on your brand’s style guide. For instance, some writers like Oxford commas, while others detest them – but your brand should be consistent in using one or not. (And if you don’t know what an Oxford comma is, that’s a good hint that you need a proofreader.)

A proofreader also identifies those little tics we’re all prone to making without realizing it. Maybe you frequently use “just” or “really” like I do. Or maybe your sentences are as long as entire paragraphs, because you pack all your ideas together instead of unpacking them along the way. Our brains know what we want to say, but we can’t always express it effectively. We all have pet errors that we simply do not see, so a proofreader helps us correct them in a way that still maintains your distinct tone of voice. A proofreader constantly thinks about your reader and polishes your text so that it’s clear, correct and consistent the first time your reader sees it.

And that’s important, because in the knowledge economy, errors in written communications don’t just reduce credibility and compromise brand positioning. They can cost money. Want proof? These ten typos cost a total of $650 million.

And correct text isn’t just important in print. Now, more than ever, it’s critical that your digital content is error-free. Spelling mistakes in an email subject line can cause your messages to be mistaken for spam, decrease click-through rates and even lead customers to unsubscribe from your mailing list. In addition, correct spelling and grammar is one of the primary variables a search engine analyzes when categorizing and prioritizing websites, measuring content relevance and ranking organic search results. Poor content quality leads to lower rank positioning, which reduces visibility and decreases traffic. Spelling mistakes can also influence search engine optimization if misspelled keywords, titles and item descriptions prevent potential customers from locating specific products and services.

Underestimating the importance of proofreading could put your brand a keystroke away from disaster. The next time you’re about to hit Print, Publish or Send, check your text. And then check it again.