For sure, I'm a terrible proofreader of my own work. I still cringe over a typo I wrote for Elegant Hotels, "there's free wi-fi in all pubic areas."
I was fired by an agency for a typo the same week I won a Clio.
In general, writers are notoriously poor proofreaders of their own work. Writing and proofreading require different skills.
UK psychologist Tom Stafford says, “The reason typos get through isn’t because we’re stupid or careless, it’s because what we’re doing is actually very smart."
Our brains trick us into not seeing errors during the self-editing process. Further, when our minds are in recognition mode, not reading mode, we tend to overlook the majority of typos.
I'm a wizard at catching errors made by other writers. Just not my own.
So I include the option of professional proofreading in my estimates. Problem solved.
Google earns $497 million every year from people who misspell popular website names and land on "typosquatter" sites.
In 2013, Macy's sent a mailer to Texans advertising a $1500 necklace for $47. The correct price was $497.
In 2006, Alitalia airlines mistakenly advertised $3900 plane tickets for $39. They honored the offer at a cost of $7 million.
In 1962, a missing hyphen in the code used to navigate Mariner 1 forced NASA to explode the rocket, at a loss of $80 million.
An e-Bay seller left out a letter in the name of a rare bottle of beer. A savvy biddy bought the beer for $300 and resold it minutes later for $503,300.
A typo caused houses in Wasatch County, Utah to be assessed at $1 billion, more than double the actual market value.