The way I used to create a keyword list for my campaigns was to use the adwords sandbox to enter a bunch of keywords that were relevant to my market and just add whatever words it spat out at me.

It took me a while but I realized eventually that this wasn't the best way to go about it. Many of my keywords would become inactive and the ones that remained were ranked 17.2 and not seeing a lot of action at all.

It annoyed me because as you probably know, on the adwords traffic estimate screen you always seem to get a number of clicks that excites you but when you actually put up the campaign the results you see are much different. Also I was always limited by the number of related keywords I could think up in my own head. I knew about the power of 'backdoor' keywords but couldn't think up enough of them up to create a profitable campaign!

The point it changed is when I found a piece of software that could I could use to see the bid results for large numbers of keywords at once so I could tell immediately which keywords were going to be the most profitable to use in my campaigns and which ones I shouldn't bother with.

Not only that but this same piece of software will actually find for me the backdoor keywords that are generally less competitive and super valuable for an adwords advertiser.

With this software I first find a market and a product I want to promote then find a website about this product... I then insert this URL into the software and it will scan all the words on the page and use certain technologies to tell me all other keywords related to that keyword that I would never have thought of!

The result? More keywords, more backdoor and hence more profitable keywords and a lower cost, potentially higher conversion ad campaign!

The software is called Brainstorm Generator and can be seen via the link in this biography box. I highly recommend it as it is a very powerful tool.