I recently got a pr5 domain (never droped 4 years old) and rebuild it to a blog. I got very SERPs with many of my keywords. But yesterday, all of them are gone. Am I in the so called sand box?
Did you recently add a lot of backlinks pointing to the domain? If too many links are added too quickly, this can sometimes cause a site to vanish from the SERPs. Of-course, your site may only be temporarily absent from the search results, it may re-appear in a few days. I've seen this a few times with my own sites. I'm not sure what causes it, it just happens sometimes. Mark
i would imagine its a temporary glitch, give it a day or two and i'm sure i will be back in the SERP's
Just be sure not to mess with your backlinks too quickly. It should be a fluctuation as stated above, wait a few days, be sure your PR remains the same and your links are only growing (no link deterioration, link deterioration=PR breaking). Let the algos keep up and keep adding unique content to your site while you are building an authoritative site. Create a user resource and keep things naturally building -- you'll be fine. The sandbox may or may not exist, I believe it doesn't, make sure your sitemaps are submitted to the SEs and ensure that all pieces of your eMarketing and site are integrated thoroughly.