I saw a Matt Cutts video a few years ago where he stated that Google 'holds' a new domain from ranking well for about 2 months. This of course is to catch and eliminate potential spam sites.
I usually take 6 weeks or so to develop a new site, so this has never been an issue. But I recently purchased a domain and developed the site in about 10 days, ha. Its been a bouncy road since.
While Google hasn't let the site rank for anything really and is holding most all SERPS back to the 4th page or further, Yahoo competitively ranked me in a few days. Then they de-indexed me. Then they ranked me. Then they de-indexed me. While they are keeping me in the SE currently, they will give me competitive rankings for several days, then take it all away.
The domain is now just over 2 months old.
Is anyone more familiar with what I can expect by developing a new domain so quickly?