There is always this narrow perfect line between over-optimization and negligent, passive optimization (or not optimizing at all). There are people who don't think about keywords at all and there are people who are consistent with keyword stuffing. There are people who press people to buy and there are people who don't use clear call-to-action.
Where is that fine line between two extremes? It is where you think and care about your prospects most of all (priority) while keeping search engines in mind. That approach is the most profitable too.
Here's an infographic from Goldilocks SEO to illustrate these 3 approaches: