One of the biggest mistakes that newbie marketers make with adwords, and other paid search services is targeting everything under the sun in one adgroup. Let’s say I want to promote a coupon site. If you use a keyword tool, such as WordTracker, you can get thousands of keywords that are related and not related to coupons.

By putting everything under the sun in one adgroup and using the same ads and landing pages for all these keywords, you are not only going to hurt your pocket (as your quality score will drop for unrelated keywords), you are not going to realize a high enough CTR and conversions from your campaigns. That’s why you should limit what you put in each of your adgroup.

The best way you can optimize adgroups is by targeting only one keyword in each group. But here is the thing. Most pay per click services limit the number of adgroups and campaigns you can have, which means you may not be able to use the one-keyword-per-adgroup concept for your adwords campaigns. I personally use the concept of “mini-themes” for my adgroups. But you should avoid putting bargain keywords in a coupon adgroup. You should also have different landing pages for different keywords. Research has shown that if you customize landing pages for specific keywords, you are going to see better conversion results.

There is no magic number that you can use here, but you should always follow this rule: never put completely different keyword phrases in one adgroup (by that I mean keyword phrases that are mutually exclusive). It’s very simple but you’d be amazed how many folks don’t do it.