online presence / 'marketing' results

I was wondering if my online presence had anything to do with sales increasing / decreasing, so I correlated the two. SALES is easy, as that's a given. For blogger / wordpress, I counted the posts I made each month and the views my blogs received each month, (wordpress is just a mirror of my blogger blog). Twitter is the number of tweets obviously. Furaffinity is a fan site and I counted the number of journals I posted and the number of art works I had commissioned. The results are thus:

Now, the first three books of the 'Duke' series were released in October, November, and March. After that, it's clear that sales were directly proportional to online effort. I do see that primarily blogger and then twitter, which alerts followers of new posts, together directly mirror sales. I've looked at each separately, and can't see that either is directly responsible for sales or that there's any relation to subject matter of posts / tweets. It's just this, the more effort made, the more posts and tweets put out there, the more views my books get and hence, more sales.

So, as we know, it's important for authors to have a blog and twitter and to stay active on them, to be an active member of the reader / writer community.