Many of our web sites are sponsored and that is how we recover at least part of the costs of maintaining them. If someone is advertising your page by way of a link, then it may well be worth it to you to pay for that link. Or it may not be worth it. In most cases you will have to look at the sponsorable site's hit rate and user demographics to get an good estimate. But in your case you can do MUCH better because you already have existing hyperlinks present on the sponsorable sites.
Most web browsers report referrer URL information to the server.
That means that when someone hyperlinks to one of your web pages, you can grab the URL from which they came. For example, one of the 6 monthly access reports that we give to each of our web customers reports the number of referrals they got from each of the places on the web with a link to their site. When you've looked at your referral information, you will easily be able to tell which sites are your traffic producers. Our World Wide Web Tennis Server is listed in some well known malls and we know for certain that these mall generate virtually no traffic for the web site. You'll need to evaluate each opportunity on its individual merits.