Unfortunately, people who come to a website via RSS almost universally have ad blockers turned on and usually are not site sticky. Maybe not the best group to attract to your site?
And feed subscribers are much stickier than most web visitors - you can't generally use a feed without subscribing to it, so anyone who uses a feed will see it again. The problem is that stickiness per se is not actually that valuable (especially when it's difficult to quantify). Feed users are so sticky that they will read everything you post but never leave the site by clicking an ad.