Correlation between App download and your site traffic?

I just published my very first app "WriteItDown" in Apple store a few days ago. I also set up a blog for it using blogger. Thanks for the real-time traffic stats of blogger, I noticed something that there may have the correlation between your blog traffic and  the number of your app download. For my case, I am able to find if the visit of my blog had a good number, so did my sale. I will keep eyes on this to see if there is indeed a correlation exist. If so, I will be able to predict the sale is good or bad before apple publish it to me.