In ensuring best results, you may use bid management tools. There are accepted and approved management tools that will help you in your bidding. They are categorized in two different types:

Web based (services by monthly subscription) or,
PC based (a bought software)

Monitoring tools too may help in the tracking down of your keywords/phrases and search engines as to which among them regularly generate sales, overall and in relation to your cost per click. This is what you call return of investment (ROI) monitoring.

These bid management tools may include additional functions that may not get from online marketing tools that are readily available. Other tools can monitor competitor’s bids, produce reports for different parties and offer the ability to interface with multiple PPC engines. This is particularly helpful to those who manage more than a hundred keywords across several PPC engines to boost productivity and save time.