Here is a screen shot of an ebook that is being featured on the Kindle site today:
If you go by the title, all you see is "How I Raised Over $35"...not that impressive an amount, is it?
If you go by the part of the cover that's readable in this small image, you will see either "Publisher Needed," or "No Publisher Needed" if you can make out the white "No" against the light green background.
The actual title of the book is "How I Raised Over $35K in 30 Days to Write My Book (Crowdfunding Tips and Tricks)." To figure out from the shortened title and the tiny cover image what it's really about probably would take more time and effort than most browsers would give it.
The moral of the story: if possible, create a title that will make sense even when shortened to 21 spaces. In this case, maybe something like "Crowdfund Your Book!" and then make the "How I Raised..." part the subtitle.
Also, make your title and image as easily readable as possible when they are shrunken down to postage stamp size.
If your book is featured, you want people to see instantly what it's about.
(for friendly guidance from idea through to publication, see my book, YOUR WRITING COACH, published by Nicholas Brealey and available from Amazon or your other favorite bookseller.)