I sometimes get asked by potential clients to only look at a specific part of their site that is not getting as much organic traffic as the client wants. While there are all sorts of strategies you can apply to parts of a site to improve its potential for attracting more search traffic, this way of thinking ignores a fundamental part of how SEO works.
Many of my clients will tell you that I often invoke Dr. House as a metaphor for how SEO diagnoses work. You review the patient, come up with some theories that apply to your past experience, start treatment and see how Google reacts. When it works, all is well. When it doesn’t, at least you’ve probably eliminated some issues as potential sources of the problem. So it’s not Lupus. Now you have fewer options to hone in on which makes solving the problem hopefully easier. Rinse and repeat.
So if you find yourself walking into Dr. House’s clinic complaining about a head cold, depending on how things have been going for him in that episode, he might just give you some aspirin and kick you out. In which case, in the next scene you’d probably be shown collapsing at your kid’s soccer game. If House had not been distracted during your first visit, he would have done a more thorough examination and discovered you had brain cancer. He then probably would have pulled out a cordless drill and had you fixed up in a jiffy.
What I’m getting at is, if you focus on fixing the SEO on just one part of the site, you risk missing the SEO cancer that is present on another part of the site. With large, complex sites, this is the case almost 99% of the time. The search engines take your entire site into account when figuring out how to rank it. So something awry on section A could seriously hamper section B’s ability to rank.
For a SEO consultant to agree that they’ll only work on one part of the site without at least investigating if there are technical issues throughout the site is SEO malpractice.