Blue Ocean Strategy by Renée Mauborgne and W. Chan Kim
has not been mentioned here and is an amazing read, and very well regarded by a lot of high profile folks.
More images isnt directly correlated with rankings but it can help increase time on site, improve user experience and lower bounce rate - all which are ranking factors.
There is no one silver bullet for SEO. Its many things combined.
If that is the case than perhaps organic traffic is not the best vector by which your site will grow.
I could make the case that targeted paid search for low comp, buy ready keywords would work well. Your content is what would push someone over the edge to buy. If you think about it, your site is much further down the funnel than other affil sites because you've vetted reviews, instead of just copy/pasting/spinning from other sites. You should also retarget the people who come to those pages with ads specific to the products they're looking for urging them to "not make a decision without all the facts" which is what you've done by mining all of the review data.
I do very much like the approach and the original idea but sadly google likes what google likes. If deeper authoritative content is not what you want to be doing, that's fine, but you shouldn't have the expectation you are going to be able to compete with the big dogs who operate in that way.
Im happy to take this convo offline as you're getting a lot of weird advice in this thread that are just random people's opinions. Shoot me an email at [email protected] if you want to keep chatting.
You guys are missing the point. Sure, he has a vision and he doesn't want to abandon it but in order to compete in ranking for super high competitive terms his site has to be on par with the other top ranking sites. Google doesn't know what his intent is and as the site is right now, the algo compares what he has to what others have. He has great backlinks, but really sub par content when you look at who he is competing against. He does not seem like an authority on any of this stuff.
If the concept is to attract the 'satisficers' which by the way, i love that word and that book also, there needs to be some other kind of optimization on the pages. Going after 'best of' for everything looks spammy. And that spammyness is amplified by the lack of content when compared to the other sites ranking for the terms he's optimizing for.
There are other ways to attack this problem. Instead of having it be best of everything - it really should be a statistics site for popular products. Add in some kind of ranking system or some kind of kayak-like search and BOOM - new unique concept that provides real value to people. As the site is right now, its gimmicky, thin on content and is NOT going to rank in today's SERPs the way it is now. Sorry.
Taking a look at your site, it seems quite clear where all your traffic went. You have a pretty great backlink profile compared to other affiliate sites ive seen but the content is incredibly thin. Based on this, me or anyone else who visits the site just sees an advertising site. There are no personal experiences with the products, the products are not related and the UX does not make the user want to continue exploring the page they landed on. The content here seems more like a statistics site for products than it is a reviews site.
The other comments here mentioning cheap as a flag word are somewhat accurate but not entirely. Its possible to rank a site using the word cheap assuming you're supporting it correctly with related content about a specific product and proper explanation as to what makes it cheap.
Honestly, I am very sorry that you lost all your traffic and your revenue but this seems like a VERY fixable problem considering your backlinks. Take your best performing posts, and dramatically increase the word count, add more photos, add overviews of each product instead of just a single line or two pulled from reviews.
Happy to help with additional pointers if you want to shoot me a PM.