The TYPO you don’t want is the wrong phone number.
The typo you do want is a typo in the first paragraph of your letter or ad.
You see, it may help response. Folks see it and feel self-righteous pride that YOU put a typo in your ad, and THEY found it.
They keep reading to see if there are more.
By the time they get to the end, they forget they were looking for more typos and become convinced that YES this is a good product/service and they buy.
Let’s talk about your marketing.