I was analysing our website with different tools including opensitexplorer, moozrank, statscrop, linked checker, seo majestic, semrush, woorank, and so on. And they all have different results to the exact same website. For example, some of them count 17 backlinks, other count 200 backlinks, then there are 14 Facebook likes and then 2 Facebook likes, and so on. The only consistent result were our CSS and HTML errors I found on some tools (25 CSS errors and 19 HTML errors). Why is that? Could it be that those tools are not reliable?