I take my smallest sketchbook with me to every single art show or art market that I participate in. I leave it open, sitting out for anyone and everyone to take a look. It's the good, the bad, and the ugly out on display right next to my best work, and people love it. Sometimes they will flip though every single page. Sometimes they will point to a drawing I hate and ask me if it's available as a print. Occasionally another artist will turn to a "bad" page, and I can see on their face that they are thinking, that's not very good. But then they get to the next page and are really impressed. Many people, especially other artists, tell me that I'm brave for sharing it, and maybe it's because they've counted how many "bad" drawings there are. Regardless, they are always fascinated by it.
I don't share my sketchbooks to boost my ego. I use it as an important reminder that there are no good or bad drawings. It is an exercise in humility, an acknowledgment that mistakes have lead me to make great things. I think it's especially good for people who wistfully look at art and think they can't possibly ever do it themselves; it's good for the people who are afraid to share their own mistakes; and it's great encouragement for kids, too. I know that I, for one, especially love to see other artists' sketchbooks. It's like traveling into a fantasy world. You get to see an interesting grouping of drawings made over a period of time from various pieces of inspiration. Looking back at my own sketchbooks, I can look at a particular drawing and know exactly what inspired it or where I was when I drew it, but other people have no preconceived notions about it - it just exists as it is, in-between the drawings on the neighboring pages. Each page is just as unexpected as the page before it was.
A few of my favorite artist sketchbooks: