Search Engine Marketing (SEM) is becoming a very popular way to drive traffic to your website. But it can also be a valuable research tool. I don't think that it should replace good search engine optimisation but merely enhance it.
The most common form of SEM is Pay Per Click (PPC) advertising and the most commonly used PPC advertising is Google Adwords and Yahoo! Search Marketing. These PPC Ads are the “sponsored links” you see in Google and the “sponsored results” you see in Yahoo. The nice thing about PPC is that you can control it and you can get instant results and feedback.
When you set up a PPC campaign, you choose what key words you want your ad to appear for and how much you are willing to pay per click. All the ads that are set to come up for that key word are ranked by cost per click, so the higher you set your cost, the higher your ad appears in the sponsored links. You then set a daily budget of your maximum total spend and once your budget is reached, your ads won't show until the next day when your budget is reset. You can also set geographical regions where your ad will be shown so you don't waste your marketing budgets on people outside of the areas where you do business.
For example you can set up a campaign for the key words “interactive marketing” with $0.15 per click and a budget of $20 per day to be shown only in Australia and within hours you can start tracking your results.
There are 2 valuable metrics that you get back from your campaign, impressions (the number of people who see your ad) and the number of people who click on your ad to get to your website. This gives a third valuable metric of a click through rate.
The overall aim is to drive as much targeted traffic to your website, by increasing the number of impressions and click through rate through the choice of good keywords, a well written and target ad and a significant cost per click to show your ad in one of the top places.