The bid you set is entirely up to you. Your maximum CPC bid should be the amount you're comfortable spending per click, taking into account your sales objectives and the amount of exposure or site traffic you're looking for. Increasing your bid allows your ad to win more auctions, and appear more frequently across the network. You can adjust your bid any time at the keyword or placement level as well as at the ad group level.
Raise your bid to get more traffic to your site, and lower it to get less clicks. This applies to ad group bids or placement level bids.
Bidding on the Search Network
On the Search Network, you might want to adjust your bids to show your ad higher or lower on the search results page. For example, if you find that your ad is performing well on some keywords but not on others, you may want to raise your bid for the well performing keywords and consider lowering it on others that aren't performing as well.
As usual, we recommend using conversion tracking to accurately measure your performance on the Search Network. This is a good way to gain the best performance on each keyword you're targeting.
Additionally, the AdWords discounter will automatically reduce your actual CPC so that your winning ad is charged only what is necessary to maintain its ranking above the next-highest ad. For guidance on how to choose bids for individual keywords, you can use the traffic estimator or the search-based keyword tool to estimate your bids and positions.
Bidding on the Content Network
On the Content Network, you might want to adjust your bids to show more or less on a given website, or on more sites across our network. In automatic placements, adjusting your bids up allows you to appear on more sites across our network, while adjusting your bids down limits your ad serving to fewer sites. For managed placements, increasing your bid allows your ad to win more auctions, and appear more frequently across the network, while adjusting it down will have the opposite effect.
As with the Search Network, we recommend using conversion tracking to accurately measure your performance on the Content Network. This is a good way to gain the best performance on each placement you're targeting. Additionally, the AdWords smart pricing system will automatically adjust your actual CPC for a given placement so that your winning ad is charged only what is necessary based on the estimation of the AdWords system that your ad will receive a click.
For tips on how to choose bids on the Content Network, or on individual placements, we recommend setting bids equal to your search CPCs, and adjusting them up or down based on your performance. Additionally, you can use Ad Planner or the Placement Tool to estimate competition on individual placements.
