Google, Yahoo and Bing are currently the most popular search engines. If you know that your audience tends to use one more than the other, your choice is clear. If you're on a tight budget, you may want to price your first-choice keywords on each search engine and go for lowest cost option.
Contextual vs. Directive Ads
Search engines offer two different types of ads. It's important to choose the one that's best for your marketing objectives.
Directive ads appear on the search engine results page and directly sell to an audience actively searching for the keywords related to the ads. Contextual ads appear next to content such as news stories. They cater to a passive audience and should be geared toward branding or awareness.
Managing Your Search Engine Ads
Whether it makes sense to manage your own search engine advertisements depends on two things: your level of experience and the complexity of your advertising effort.
Your Web hosting company may offer a service to develop keyword lists, manage your keyword bids and provide you with reports. To manage your campaigns yourself, contact the search engine you plan to use, and follow the sign-up instructions.