Hi Mario,
Thanks for your reply! Hmm... the thing is we honestly haven't paid for any links at all ever. The listing on linksjuice.com was premium because we put a reciprocal link in an old blog post. Are these types of big directory listings things that Penguin targeted? Because a number of our competitors (who weren't affected last year), are also listed in similar directories. A number of the directories we are in now are only recent additions (a month or so ago, in response to our big drop in traffic 8 months ago).
Did you find our most common anchor text from open site explorer's 'anchor text' listing? The anchor text you mentioned is only used 5 times according to OSE. There's 'trampoline australia vuly trampolines' as img text, did you mean that one? That's just one website who has a badge on each page of their website.
We started a campaign in April for our authorised resellers to have a badge linking back to our website, not for our primary keyword, but to our trading name and company name. We aren't paying or forcing them to put it on or anything, we have some very loyal resellers who love our products, and there are also some that are fake (which is also one of the reasons we started this) and pretend to sell our products but ship other low quality models.
We have a SEO company that also does work for us on link building sometimes as well. Thing is, I never know what they do or what links they build for us. We have left it totally up to them and never done any of our own link building until a few months ago to try and get back up.
So do you think it could still be a bad back-link thing? If someone were to link to our website's homepage, and we want to rank for 'trampoline', should the anchor text always be trampoline? That's something Google has been trying to fix up with Penguin isn't it? Noticing when its all the same anchor text and ignoring some of the links because of it?
If you look at linking root domains, you'll see stuff like stackoverflow, css-tricks etc (these are all from when I've posted and used my website's URL in the website field). Could this have diluted our ranking at all? Google should be smart enough to recognise that?