I wrote an ebook about a non-technical topic I had experience with. I spent 18 months doing all the things I was "supposed to do" to build traffic and sell cop

I wrote an ebook about a non-technical topic I had experience with. I spent 18 months doing all the things I was "supposed to do" to build traffic and sell copies of it - frequent blog posts, SEO (including some recommended grey-hat stuff), weekly "newsletter" e-mails, etc. Before the Google ranking algo change (Penguin? Panda?), I had my best month ever - US$ 150 in gross income. After the change, I lost 90% of my traffic and didn't have the heart to continue. Even without the traffic loss, the site was going nowhere, due to a bunch of other mistakes I made. The biggest problem was that the maximum lifetime value of a customer was less than US$ 25.