I searched yellow pages 411 in google and it gave more than a million results. 411 has some significance!
411 is a phone number that you used to ask for phone number listing (like a directory) in United State and Canada Yellow is the yellow books i believe, which is book of local directory
411.ca and 411.com are basically online white pages. The Yellow Pages have business listings. Thus, Yellow411 is probably meant to be some sort of directory. However, I doubt it has any value.
411 is traditionally know to mean "Information". "Back in the day", you would call 411 to get phone numbers and addresses, actually I still do from my cell and land line. So "Yellow", and "411" would be both terms known for information and directory listings. It's a double whammy.
Information and a huge advertising network here in Canada and the United States. Check for patents and such on it first just in case or develop it out not with phone numbers and addresses