Keyword in domain

If "Halo 4" is my main keyword, and I register a domain as halo4land, will that register the keyword as "halo 4" or "halo4"? The reason I ask is because the search results between "halo4" and just "halo 4" show a pretty big difference. If it won't register as "Halo 4", then I will make it haloportal, or something like that, because there are more searches for "halo" than "halo4".

It depends of what the anchor texts(from link building) will show.
If you optimize for "halo 4", so will the search engines aknowledge your site.

Google can't read space in domain. Exact match domain still best. Try to add "s" or other suffix.
Posted via Mobile Device

It looks like you have a long way to go on your seo journey...

but google will rank you for whatever you optimize for. It's all about the anchor text for backlinks. I'm sure you'd like to rank for "halo 4 something" so make that your anchor text. Essentially the more backlinks you have with that anchor text, the higher up in the search engines you'll be.

To place your main keyword in the Domain is not going to make you rank up it will help of course. However look at Facebook! It comes down to hard to hard work and experience. You need to add fresh content whilst also placing in decent back links on there.

You should spread the word by creating accounts on the likes of Facebook, Twitter, StumbleUpon, Reddit, to start with and make sure you get your Onpage SEO correct as well. Onpage SEO adds more than you may think to the over all value.