I wasn't really certain the census entry in Union County, Ohio, was for the right James Kile. The index entry and transcription didn't indicate the names of the others on the census page. As soon as I saw the image, I knew I had the right person as three of his sons were listed on the same page. Sometimes you need to see the entire document to make certain it's the correct person.
Not to mention the occasional additional clue that pops up.