Search engines call asterisks (*) and underscores (_) wildcards. They can used in many different ways. But for search marketers, wildcards can be extremely valuable in finding out strategic keywords to target and in estimating total search volume.
The secret is in the autosuggest functionality of search engines.
The above image is an example of how you can determine search volume by omitting a word at the beginning of a query.
This can obviously be of immense value in many forms. You can place the asterisk at the beginning, middle, or end of any phrase and document the suggested phrases. From there, you could place all of these queries in a search volume tool to determine which are worthwhile (for either SEO or PPC).
A lot of search marketers don't realize that you can also use underscores for the same effect.
I love using the wildcards in the center of a phrase (shown above). It can open up a very specific pool of most popular keywords in any given set of words.
Whether you're an SEO or just a Googler, using wildcards can help your search experience. Give it a try and leave your helpful hints below in the comments section.