Since I started online marketing I had only medium to low competitive projects. Soon I will be involved with doing SEM and SEO project for a global e-commerce player (examples might be real estate, hotels, flights niches on a global scale). Their websites already have couple of millions of backlinks, still it's not even close to enough to compete with industry monsters who seem like stuck with super glue to the 1st SERP. I know to succeed SEO will not be enough, there must be banners rotating on major platforms, paid google ads optimized everyday, affiliate programs introduced etc. But in terms of SEO and link building what would be the best advise from someone who have experience? With future SEO budget, I am surely will be able to subscribe with tens of BHW high pr backlinks providers, but will it be enough? Should I pursue long tail or target the most hard keywords? Really need some expert help from an experienced BHW member.