I'm not thinking of providing direct SEO services to the companies in the same industry. The app would simply allow them to check and validate their seo strategies and see comparable data for all the other companies in the same industry (on-page and off-page seo stats, back links etc).

At the moment, I'm not confident that there is any niche-specific value the app can provide to the companies. However, assuming I can figure that out, would a company really be put off if their competitor was able to access the same value?