Welcome to the Q&A Forum

I'm at a loss and no so-called SEO agency/expert I've hired appears to know the main causes of our post-Penguin downfall of our traffic. To set the scene, I set up a voucher code site (www.ozvouchercodes.com.au) in Australia 3 years ago and since, it's been growing very well up until Google launched the Penguin update in April. Having read as much as I could on the update my understanding is toxic links cause the slap.  For on-site I've checked the site and tried to reduce keywords [spamming], increased [unique] content across the site and made sure there are as few instances of duplicate content as possible. To attempt to understand my back link profile I've used SEOmoz & Link Detective as the current SEO agency give me little visibility on this. It appears we're a little top heavy with 32% & 11% of are keywords containing 'coupons' and 'promotion codes' respectively.  Consequently we no longer appear on those two terms but also hundreds of other terms we once appeared in the top 3 postitions. The Link Detective report downloaded also appears to have a number of back links with the words 'Penalized' and 'Banned' next to them.  Unfortunately there is no explanation on Link Detective whether this needs action or not. My current SEO agency suggest that we have been too focused on a limited number of keywords and that a few more months of diversifying the range will solve it. So do I spend another £X amount for 3-6 months of SEO or drop the site on a new URL and start again. Any ideas? Any help is very welcome & appreciated. Henry