I recently purchased a new domain for my height increase blog versus an older clunkier domain name and I think it was a mistake. First, Google Friend Connect and Google search stopped working properly. And now Google Webmaster Tools and Google Adsense are messed up.
The reason I got the new domain for $10 was to simplify the domain name. Blog and spot are not keywords and also you can now get to the site just by typing in http://heightquest.com. I'm not sure if this was worth all that it messed up. Google is supposed to automatically redirect but it seems to be as though the two sites are two separate entities which are fine if you bought the custom domain name in the beginning but if you bought it later... Oh, I just checked and it is now correctly redirecting towards height quest. It is still displaying The Quest for Height domain name in search results so I'm worried that some link juice may be lost.
I also thought maybe I'd be able to get double link bonuses. I could link to the blogspot domain from one c-class ip and then link to the regular dot com from that same c-class ip and get the same link juice bonus.
According to Scroogle dot Org I'm nowhere in the top 200 search results for height increase. I do rank around number 17 for growth plates though and I'm number one for grow taller IGF-1 spots 1-4 so it could be other factors at play like me not using the keyword height increase enough on the home page(although I do have it in the external links).
Anyways, I think if you decide to buy the custom blogspot domain you should do it right away before you get any traffic to avoid confusion. I'll do my best to adjust.