long tail has nearly become irrelevant on google i found. if you bid on say "re-mortgage my house as i am going too far in debt" You are going to get a c**p quality score as google hasn't enough data to give you any quality, so you'll get the standard 1.30, 6.50 min bid. Extremely targeted term, but because it's not good for google's pocket to let you beat someone on broad match on "mortgage" paying $5, they have invented this quality score
i tried long tail keywords with each of the 3 options (for 10 days each).. tho number of hits was higher for broad match, ctr was better for exact... tho for highly targeted (EXtra-long-tail) i agree wid briggidere.... the quality score goes too low.. and i personally try to stay away from them...
i agree wid briggidere and absinthe.... Longtail keywords have also proved useless for me.... hardly any conversion.... or clicks for dat matter..... ( just one over hyped aspect of PPC marketing by some so-called PPC gurus to sell their silly e-books)
Perhaps better to concentrate on popular (shorttail) keywords that have been overlooked - Reading Chris Anderson's 'Long Tail' right now - fascinating book, highly recommended.
Long tail bidding requires a different mindset and doesn't work if you're looking at things over just a 10 day period. Think years. How many times PER YEAR will someone type in that phrase? Google hates them because they clog up their system and don't generate nearly as much revenue as the popular phrases do. All adwords cares about is getting money out of your pocket. They dont' care if you're making money or not. If you were to a million long tail phrases into adwords, you will most likely get slapped, not because it's not a worthwhile venture and would make you a very healthy ROI, but because Google won't make as much money off you.