The art of showing your site on the first page of Google hasn't changed that much in the past decade. It somehow has got more difficult because of the competition and the new google algorithms. But after all the main technique is the same, you will get as many backlinks as possible to your site and from reputable website and hopefully from the same niche and you will get a boost in Google rating.
SEO Hosting is a service aimed at search engine optimization professionals. The ones that have a network of sites and then they provide back link services to their customers. The main problem for people who have many high quality (reputable) sites is that they have to be able to hide the relation between their sites from Google or they might end up being deindexed.
One main approach is to have the sites on different networks/subclasses and that is what a seo hosting company provides. Option to have all your sites on different networks yet manageable from a single panel.