I am researching a niche. I did a SEO competition report on the same using MS and found some authority sites being beaten by more newer site. So, I decided to follow my competition a bit to find some more easy niches . Now the issue is that even with yahoo explorer I am unable to find the social bookmark done by the competitor. I know it can be done as I was able to find one of my competitor on Diggo and he gave me a $2.5 a click adsense keyword with 4000 searches and 1 competition (only him) .