See http://instantdomainsearch.com/articles/faster_domain_name_s... and (very brief) HN discussion: http://news.ycombinator.com/item?id=3045333
Something similar happened when I launched http://hnnotify.com -- got 24 up votes and then it crawled into oblivion <shrug>
See http://instantdomainsearch.com/articles/faster_domain_name_s... and (very brief) HN discussion: http://news.ycombinator.com/item?id=3045333