It depends on who you are and which keywords you buy. Consider the recent study done by eBay researchers, who disabled their paid Google search advertising to track the benefits of buying branded keywords—and found that they were wasting a great deal of money.
The researchers discovered that many of their customers were loyal buyers, people who had used the site before, or people who were familiar with eBay’s products and services. Put together, this left very few customers who were new and needed the website suggested to them—the very group of people paid search ads are meant to target.
The only real benefit paid search ads generated was a slight increase in eBay customers who were looking for a particular item that they did not know was available on eBay, such as musical instruments or wholesale items—and even then, profit was minimal.
Simply put, eBay’s paid searches were ineffective because they were too well-known. Customers who had previously purchased items on eBay were likely to do it again, and those who had sold items on eBay were well versed in using the website.
As the eBay study proves, paid search ads are only effective for certain businesses—and only then, if used correctly. For example, there’s no need to purchase keywords containing your law firm’s name. As long as you are the only firm operating in your area with that name, your name will appear in a “natural” (unpaid) listing, which will appear at the top of the search anyway, without your wasting money to have it placed there.