I stumbled on this article recently revealing that in testing on sites like Vast.com and Kelley Blue Book, having a “Mad Libs style” form can increase conversion by 25%-40%.
The way this style works is to have the fields you use to collect information from visitors formatted to be a part of a paragraph(s) of copy. In this way the visitor reads through the paragraph, filling in the blanks with their information to complete the form. This is opposed to a more traditional web form that merely puts up a list of fields that to collect information with.
I suspect that this different format reads much easier and engages the visitor in a more interactive format. I can remember playing Mad Libs when I was a kid and it was definitely fun. I can imagine that this style of form formatting could ad just a bit more amusement to the seemingly boring process of filling in information.