We have three different websites. All of them have their main domain name and then multiple other domain names that also point to them. We want to get a web host that we can have all the sites on one account with multiple paths. (Different folders, and each folder is a different domain name.) Does anyone know how this effects search engines? Is it good or bad - or does it even matter at all?

every hosting package would state how many domain name or website would one account host. some packages would host 1, 5, 8, 10 or unlimited domain name etc. so you need to carefully look at the details. unlimited domain is not advisable because it would slow down things because you are using shared hosting. you might have only 3 website but others who is an domain name auctioner would host 1000 name. domain name use up resources and that would always translate into loading time delay. if those sites of yours are in different theme that would be good. you can connect them together in some kind of a network. if you need info seo you can go to my site thru my profile and check out website building section. for hosting recommendation you can check out below resources. hope that helps a bit.

Just make META entries and everything should be fine.