The problem comes just after you click "download" and realize you have a 600MB XML file listing the Ph levels of groundwater sites around the country for the past 25 years. How in the hell are you going to make that data an interesting draw that users want to read or learn about?
I have no skill for frontend design, but I've recently begun to learn how to display data in an intelligent manner. If anyone is interested, these books have helped me:
Information Dashboard Design: http://oreilly.com/catalog/9780596100162
Visualizing Data: http://www.amazon.com/Visualizing-Data-Explaining-Processing...
Beautiful Data: http://www.amazon.com/Beautiful-Data-Stories-Elegant-Solutio...
People are probably looking for that data. Find out exactly what they're searching for, and tailor your content/site presentation around those keywords. You can use Google Keyword Tool to find this information:
Developers need to know how to display data in an easy to understand, easy to follow, and easy to consume manner in order to get people to the site. Keywords and SEO only go so far. You still need readable content for humans.