A typo is when you hit the wrong key—hence the word “typo,” short for “typographical error.” It could even be because you—one time—typed the wrong word in a manuscript, such as “to” for “too.” It happens.
When it comes to social media, though, I expect the writer to make that correction as soon as possible. It’s a little different than going through an entire manuscript; sometimes those just don’t appear. And I mean one time, not continuously.
See, if you consistently use the wrong word, to me that means you don’t know the CORRECT word. As a writer, you should. It’s part of your trade, your art, whatever you want to call it. Just like a carpenter would be expected to know how to use a hammer and saw—you, the writer, should know how to use words.
Don’t say, “Excuse the typos.” Have some pride. FIX them.
Some authors swear they don’t “see” errors when they read; they’re caught up in the story. I have to say, I’ve NEVER been so caught up that I miss repeat mistakes. And it detracts from my experience as the reader—any distraction from the story will, in my opinion, and should, lower the rating given to a book.
Maybe it’s word usage; maybe it’s misspellings. Maybe a hyphen instead of an em dash. Maybe a word repeated not only throughout the book, but used in sentences that are in close proximity. That’s what editors are for—to catch all this stuff.
But the author must take responsibility too, first and foremost. After all, in a professionally published book, the editor isn’t listed by name. It’s the author’s book.