If you are spending money at any of the pay per click search engines make sure there are not dramatic bid gaps happening. Daily bid management plays a pivotal role in ensuring you receive a positive return from your advertising budget.
You may have seen this phenomenon when managing your bid for placement account. Your listing appear in the number two or three position and the site above yours is bidding dramatically higher - in some instances so much higher that it makes you wonder if somebody has a score to settle. While there may actually be a logical reason there is simply no excuse for this oversight - if you are responsible for managing bids - make sure you log in to your PPC account and make sure this is not happening to you.
Some PPC's, namely Overture, automatically default your listing to the first position when you add new terms. So if you don't set a maximum bid initially, you are going to be bidding one cent higher than the highest listing unless you lower your bids accordingly to make sure your costs do not exceed any potential profits. A reason you may see bid gaps (or what seem to be bid gaps) at smaller second tier pay per click providers is because these networks routinely share advertisers' results with several other search, portal or directory networks. Just because you are in the first position at one PPC however does not mean that you will be displayed in the first position at their partner sites. This is why advertisers routinely bid what appears to be dramatically higher - to receive placement on a broader netowrk. If you take this network bidding approach, it's crucial that you determine the optimal cost per click and this can typically be achieved through active monitoring of your ROI.
Whilst small volume phrases, in most instances, require less management than high volume phrases, high volume phrases will present opportunities to exploit gaps in the bidding where competitors' budgets have been consumed or daily bid caps met. It is common for gaps to appear towards the top where vendors are bidding large amounts for high volume phrases. When this happens it often presents an opportunity to climb into a top spot on the bid ladder whilst maintaining a similar bid price. The importance of this is such that this media needs to be actively managed on a constant basis. Those that treat this as a traditional media buy in that they pay for x amount of inventory, check the results at the end of the month and renew again for the next month, typically produce insignificant returns for their investment. So Mind The Gap!