With your adwords campaign its possible to get excellent results when using proper keyword matching. Google offer the options of Broad Match, Phrase Match, Exact Match and Negative Match when setting up your key words and phrases for your online advertising campaign. By effectively using these features, its possible to create what is referred to as an Embedded Match.
According to the Google help page:
(https://adwords.google.com/support/bin/answer.py?answer=6100&hl=en_US)
What are keyword matching options?
There are four different keyword matching options, each specifying a different way for a keyword to interact with search queries. With some options, you’ll enjoy more ad impressions, clicks, and conversions; with others, you’ll get fewer impressions and more narrow targeting. By applying the appropriate matching options to your keywords, you can best meet your ROI goals.
Your options are:
Broad Match – This is the default option. If your ad group contained the keyword tennis shoes, your ad would be eligible to appear when a user’s search query contained tennis and shoes, in any order, and possibly along with other terms. Your ads could also show for singular/plural forms, synonyms, and other relevant variations. For example, you ad might show on tennis shoe or tennis sneakers. Run a Search Query Performance Report to see what keyword variations trigger your ad. Check out this blog post to learn how broad match can help you reach more customers (English only).
Phrase Match – If you enter your keyword in quotation marks, as in “tennis shoes,” your ad would be eligible to appear when a user searches on the phrase tennis shoes, in this order, and possibly with other terms before or after the phrase. For example, your ad could appear for the query red tennis shoes but not for shoes for tennis, tennis shoe, or tennis sneakers. Phrase match is more targeted than broad match, but more flexible than exact match.
Exact Match – If you surround your keywords in brackets — such as [tennis shoes] — your ad would be eligible to appear when a user searches for the specific phrase tennis shoes, in this order, and without any other terms in the query. For example, your ad wouldn’t show for the query red tennis shoes or tennis shoe. You likely won’t receive as many impressions, clicks, or conversions with exact match as you would with broad match. However, if you’ve carefully constructed a comprehensive keyword list, the traffic you do receive may be more targeted to your product or service.
Negative Keyword – If your keyword is tennis shoes and you add the negative keyword -red, your ad will not appear when a user searches on red tennis shoes. Negative keywords are especially useful if your account contains lots of broad-matched keywords. It’s a good idea to add any irrelevant keyword variations you see in a Search Query Performance Report or the Keyword Tool as a negative keyword. Learn more.
Remember, no matter which matching options you use, it’s important to only use keywords that accurately describe your product or service.
What I like about this whole system is that if you use these options together, you can creat an embedded match, which is able to help you run an incredibly effective campaign.
Setting up an Embedded Match
To start a basic embedded match campaign, setup three different adverts for the same website, these adverts are going to be shown at the same time, but to different users, depending what they search for. As such, each advert should be targeted for that specific user/visitor profile.
Advert 1 = Exact match advert
Make sure all the key phrases in this advert are in [square brackets]
Advert 2 = Phrase Match
Make sure all the phrases in this advert are in “quotation marks”. Once you have these setup, also add negative -[exact match] key phrases, use the same ones as in your first advert. What you are doing here, is targeting the phrase, but NOT showing the advert at all for the exact matches on advert one. So advert 1 and advert 2 will always be shown seperately.
eg: “key phrase 1″, “key phrase 2″, -[key phrase]
Advert 3 = Broad Match
In this advert, simply type the target key phrases without the square brackets or quotation marks. Once you have all your key words, also add negative “key phrases”, so that your advert is not shown when a user searches using your exact phrase. eg: key phrase 1, key phrase 2, -“key phrase”
By doing all of this, you have segmented your target audience, and can create adverts specifically for each demographic. If you think of a dart board or target, your bulls eye is the traffic from advert 1, the second ring is the traffic from advert 2, and the third ring, is the traffic from advert 3.
That is how you setup an Embedded Match. Hope you find this useful, it works like a charm for me 
Cheers for now