I had spent 6 months backlinking for a what I consider a major keyword and things starting rocking. But then for the last 4-6 months my site lost rank. I was pretty sure the mucho backlinking wasnt a factor based on countless testimonies here on BHW. The consensus here on BHW is there is no such thing as a bad backlink. Was unable to pinpoint where I went wrong. I tried many many many changes. Then today I was able to pinpoint it. I had a list of the top 50 cities and the top 50 states of my home page. Worked for a few days. I came up for my keyword and the corresponding state then I dropped off. Well googlebot is much smarter than all of this. You must have a separate page for each city and state. Old news for sure. I took the list off the home page and within a few hours I am back on top. If you are sandboxed and have a list of anything on your site test it by removing it. Its easy to get stuck in the early days of SEO and forget that we are well past the point of keyword stuffing via lists. Sidenote. I have also made my sites more trustworthy by linking to well trusted .gov sites in my industry. My competition does this and are Number One. I suspect googlebot thinks several links to a public service site in your industry is worthy of some weight. Shows concern for the general public on your part, although in reality is BS on your part.