Recently I started cheating by using WordPress themes. It saved hours of development time, and the sites look great. But for some reason, as much as I did to optimize them, they never ranked well. Every SEO report I ran ranked them extremely high, but they never reached better than page 3 or 4 in SERPS. Other pages that looked like shit, and not nearly as streamlined as mine were ranking much better. I was baffled. So I started to cross test sites on search engines, and my conclusion was that the themes I used ABSOLUTELY CRUSHED my SEO implementations. And you could be having the same problem.
Especially if you're using Themeforest themes! - which are probably the most popular themes to use. They look great and they're super cheap @ $40 a pop. But are extremely bloated, and SUCK for SEO.
There are a number of reasons, and for the sake of a shorter post, I won't go into great detail. But if you're using WordPress themes, do your research. Don't use a theme just because it looks nice, make sure it "works". Otherwise you'll have a great looking site that no one will ever see, much less find.
Here are some great articles to read at your leisure. Most of us are developers and this is our living. I took the time to test and research this to help myself, but I wanted to post here to save everyone else the time and headaches. So if your WordPress site isn't ranking well, or it is losing ranking...look no further.
I hope this help!
Why I No Longer Use Themeforest
10 WordPress SEO Questions That Took Me 10 Years To Answer!
Best SEO Optimized WordPress Themes to Use