2 or so weeks ago I made a website on a brand new domain, built a ton of backlinks, and got this website up to #1 for a term in Google, but after 2-3 days, it disappeared for that term completely. It wasn't banned, it's still in Google when I search the domain up. I'm not sure how long it will take for it to start ranking again or even "reappear" for the term I'm trying to rank for, but I was thinking of registering a new domain and making a new website using the same host. Would there be any problem with this? Or would my new website get the same treatment because it's hosted on the same IP? I'm planning to build backlinks slow and more naturally this time around.
No I don't think there will not be any problem even if you create a new website on the same host with the same niche as the previous one. This time around, just make sure that the links increase slowly so that it will appear natural. If you don't have any links between those two, most probably the search engines will see them as totally separate sites which doesn't relate to each other.
I don't think it will be a problem as long as you don't heavily interlink the two domains. However I think your new site will share the same faith with the old one, so why don't you just wait for a few weeks and work on some other project in the meantime? Pushing really hard in Google is not a very good idea.
It's quite normal for listings to disappear and reappear over time, sometimes for days at a time. Sometimes they may completely disappear, other times they just go down to page 2,3, or whatever. A brand new website with a heap of backlinks is a pretty big flag to google though. As for the ip address, it's likely to be flagged somewhere, but whether you get flagged negatively for it is another question. Google would be well aware that web hosts host multiple sites on the same IP, so I doubt they would penalize you without at least determining if the other domain is also owned by you. Are you domains registered with private registration? If not google will find it that way, and realize it's the same person (if indeed they have a problem with what you have done). Google is also a domain register, but there is opinions on both side of the fences as to whether that means they can see "through" private registration. I believe they can't, although they may be a slight time window between when you register and when privacy is enabled. Some domain registrars don't allow you to put privacy on immediately... Personally I'd just give it a bit more time, and may go a little easier next time. By the way, it also depends on the type of links... Cheers
How old was the site ? google often ranks new sites very well and than assign it a more permanent position in few weeks time. So u may have been done by that.
Since it is a new site, Google will put you in the Sandbox. If you make a new one again, Google will put you in the Sandbox again. If the domain is not 1 year old, don't waste your time. Buy an existing site, and add to that one. And if you get "a ton" of links to a new site from any source, G will bust you.