Links to other sites can be good, but you need to be sure that they are relevant to the theme of your site. Offer things on your site that are free. You get the idea. The more the better. However, be sure that these are quality freebies.
Nobody likes cheap and sleazy stuff.
It may take a little effort on your part, and some negotiation with other webmasters, but will be worth all your efforts. You will be building a rapport with these surfers. They will remember where they got that terrific freebie and come back looking for more. If your site is well laid out, and easy to navigate, in other words, user friendly, and you have more things on your site than what they have time for, chances are they will bookmark your site and will return at a later time. The more often they return, the greater the chances are that they will purchase one of your products or services.