Clearly define your objectives in advance so you can truly measure your ROI from any programs you implement. If the usability of the web page is bad, users won't be able to find the great content and your link. Is the page with your link easy to navigate? Is it easy to find your link? Does the web page load fast enough? There are a number of methodologies ranging from complex formulas including many different heuristics to more simplified models designed just to give you a sense of the opportunity. Research your competitors