Relative bidding is used when you want your listing either above or below another specific listing.

This other listing could be a site you work with that is complimentary to your own and you want more real estate space at a certain position or it’s used to be directly above a specific competitor.

You can specify one other website, and when your pay per click manager makes bid updates, this other site will be specifically looked for, and if found, will create your bid either directly above or below theirs.

If you are having a price war (not pay per click bid prices, but merchandise price) or other direct competition procedures, this can be a useful technique to be found just before your competitor.

It should only be used in specific instances as there are other bidding techniques that will get you more exposure or lower bid prices without worrying about your competition.