How Do You Find Your Long Tail Keywords? Adwords Broad Match or Keyword Tool?

Which method do people prefer to use for discovering Long Tail Keywords when using Adwords?

Broad Match - Enter some broad match keyword then review the Keyword Match report and move the performing keywords into exact match, and the non-performing into negative match. Typically it is best to use the precise broad match by putting the + sign in front of the keywords. Otherwise in my experience, the broad match is way too loose and you risk incurring very high costs with very low ROI. Which is the major downside to this method as at first, you will have low ROI due to paying for clicks for non-performing keywords during the 'discovery' phase.

Also you will need a minimum amount of click-thrus to determine if the keyword is performing. That minimum amount is based on the minimum conversion rate you need to break even. For example, if a conversion makes you $100 profit and the CPC on the keyword is $1, then you won't be able to determine it is non-performing until you are at or close to 100 clicks. The reason being you could have 80 clicks with no conversions, but then get a conversion on click 81 and now you have a positive ROI keyword. Unfortunately on many long tails, by definition of being a long tail, the traffic is low, so it could takes months, maybe even years to reach that minimum data point. So you may have to make some predictions base on looking at the total data on a group of very similar long tails.

The other method is of course using the Keyword Tool. Using this method you reduce the amount of money you will have to waste discovering long tails. But you may miss some sales. You can use your intuition as to which long tails are most relevant and therefore have the highest probability of a positive ROI. The downside of this method is that it is time consuming (but only at first) to go through and evaluate and choose all the keywords, AND, more importantly, the Google Keyword tool will not show you all the possible long tails that may produce conversions for you. We have discovered this over and over seeing conversions on very very long tails that had we not had the broad match active, we would have never got the sale on that search because it was too low of volume to show up in the Keyword Tool.

Personally, we are finding for most campaigns that it is best to keep broad match (precise +) keywords active but just keep adding long tail matches that are obviously not relevant to the negative list via exact or phrase match.

Example: You have a broad match: +brand +widget +sales And you get a match on the search: chicago brand widget sales but you don't have a store in Chicago (but you still want to advertise in that market for online sales so you can't use geographic targeting on the campaign to exclude this match). So then we would add chicago brand widget sales to the negative list. Unfortunately by that time, we already paid for at least one click. But the same broad keyword may have brought in a sale on the search "really cool looking brand widget sales" which only had a couple impressions and didn't show up on the Google Keyword Tool but only needed once click-thru to produce a sale!