new domain indexed in 4 days

[David16]

Hi everyone
I have been reading in the forum about the "sandbox" effect and how some of you suggest just putting up a holding page for a new domain until you need it. I though that was a good idea so I sent a new domain live last thursday on my server and put up a one page "launching soon" on the domain. I then just put a simple link from one of my sites link directories to it (giving the new site no preference). I got a google alert to day of the link and the new domain was indexed by google on Sunday. I thought that was pretty quick. I am going to see how long it takes for the other engines to index it and not going to use any submission software.