Your site dropped in SERPS probably because you were doing something wrong. You were lucky to have a good ranking in the first place so count your blessings. What probably happened is google went through and analyzed quality scores. Found that other sites have better relavance than yours, so they came out on top. Keeping good content on the site is always a plus. Also targeting more of a smaller niche, micro niche, would help. You faced saturation and your site couldn't hold up. You can't just build a phpbay page and listings to the ebay product and be done. Add reviews and posts on the products. Offer alternative products, and post on them. Pick something within the niche of your site and post on it once a week. Afterall, the site really is a blog. Google likes fresh content. You cant provide, you get G-Slapped.
