Reading a book about losing a pet might help you grieve the loss of your own, especially if you’re a kid. For one author, deciding on a children’s book title for a story about losing a dog was a challenge of its own.

So, the author put three options up in this PickFu poll and asked 50 dog owners which title made them more likely to buy the book:

• A: When Winnie Went Away
• B: Where Winnie Went
• C: After Winnie Went Away

The titles are similar. But, as the results of the poll show, one word can have a big impact on potential readers.

Can you guess which one won?

When you’ve narrowed a book cover down to two nearly identical designs, how do you choose the final version? In the case of this author’s PickFu poll, small details made all the difference.

For a book titled Painful: One doctor’s fight against the Opioid Epidemic and Big Pharma, the author asked an audience of mystery and crime readers the question, “Which book cover is more appealing?”

Both covers feature an image of a pill bottle. In Option A, the bottle is on its side and the pills are spilling out. In Option B, the bottle is upright, with the pills gathered neatly around.

Can you guess which one won?

In the oversaturated market of fitness books, one of the best ways to choose a book cover that will stand out is to split test your choices with a highly specific audience.

That’s what one author recently did on PickFu with three potential book designs. The author asked a target audience of people who take nutritional health supplements daily and who read self-help books, “Which book would you pick up in a store?”

The books have the same title and subtitle: 50 Fitness Tips You Wish You Knew: The Ultimate Collection of Tips, Tricks, and Hacks to Transform Your Mind, Body, and Life.

But the covers are wildly different.