Submit targeted keywords

Submitting an extended list of keywords may not be useful. In fact, you won't get as many potential customers to your website with an extended list of keywords as you would with focused and targeted keywords. Besides, you would also end up paying more without any benefits.
Targeted keywords would ensure that only those visitors who are actually interested in your product or service click on the search listing and visit your website. Thus, there are more chances of a visitor becoming a loyal customer.

Develop a catchy title and description

When the search engine user gets the result of a search, they'll see the highlighted titles for each listing followed by a short description. You should think of this just like a classified ad with a headline and short copy.
Here are some tips for formulating effective titles and descriptions:
• Use an attention-getting headline to get as many people as possible to read the description. Here's where you want to be sure to use the important proven successful terms like “free” and “you”.
• Write a description that succinctly tells the reader why he or she would be a fool not to click on your link. For most keywords, this is the best plan because you're only paying a penny or two for the click-through. But, you'll want to be more selective about the copy for the more expensive bids. If you're going to pay a quarter for each click through, then you may want to have higher quality traffic. You don't want just anyone to click through. You want people more likely to buy.
• You should have the ability to track each keyword so you can determine the success ratios of clickthroughs to sales. All programs discussed above will allow you to use their system to track clickthroughs.

ROI Tracking Tools

There are several tracking tools that measure the traffic coming to your website and that can identify what search engines and what keywords have brought that traffic. Moreover tracking tools can also tell you what the visitor has done online, including page visits, time spent, actions taken (relevant for e-commerce sites or query/contact forms) and so on. You will have to find your survey methodologies to relate the traffic history to the revenue results. Some of these are mentioned below:

Doubleclick's DART paid placement and advertising ROI tracking tool generates web-based reports on cost per click, number of clicks, overall media cost, conversion rates, gross sales, return on investment (ROI), and net profit. Such tools are suited to online merchant sites.

WebTrends from NetlQ: Offers server-based software to determine how many visitors are coming to the Web site, where they're coming from, what they're doing on the Web site, and which search engines are sending the most traffic, along with which phrases drive the most traffic from each search engine.

HitBox from WebSideStory: It uses a different data collection method, by enabling site owners to add code to their site. It tracks the same type of information that the WebTrends product does.

Urchin: This is another useful measuring and tracking tool.