This question might be really stupid, but do you add keywords for terms that show no green bar at all for Search Volume? I tend to add keywords with a bit of green bar and Advertiser Competition is low. Is this the right strategy? Thanks in advance
well if there is no one searcing I guess it wont hurt you. But google wont keep track of every keyword.
I wouldn't rely on their estimates as they've been known to be way off. Just do your own testing and see.
The estimates are inaccurate, but even if the traffic volumes are low, the long-tail can be very worthwhile. Suppose this keyword has 10 impressions per day. If you get a 5% CTR, and 5% convert, then you'll get one conversion every 40 days. But if you have 1000 of these keywords, then you're getting 25 conversions per day! Generally, very specific, low traffic keywords will be cheaper than more generic ones, and will convert better. For example, you'll get a lower cpc and better conversion rate on "Dell Vostro 1700" than on "laptop". Of course, the large traffic volumes are on laptop, which is why people bid more on them, but you should certainly try the long-tail, as long as the keywords are relevant (don't bid on the above if you don't sell Dell computers, for example)...
Think of your own search behaviour. When you start looking for a solution you tend to use very broad keywords in your search. "executive cars" Once you have found what you are looking for you will tend to search again with a more specific keyword "5 series BMW" When you are ready to buy or compare prices you will be very specific "used BMW 525i" Not many people will search for a "used BMW 525i" but which keyword will generate the greater return?