Well it worked for me, I was able to narrow down were a relative lived in the 1930, and 1920 census, and by looking throught the street index I started I was able to narrow down were to look for them in the 1900 census.  After looking at two images I found them. 
With this information I was able to find them, which I was unable to find them in a regular search.  It helped me get a birth month/year for both Anna Gerrity Mckenna, and William Mckenna, right now I know Mckenna died before 1920, and he was from Ireland, so 3 new pieces to the puzzle in a little time.  On to the next name.