Allow visitors to comment, or even let them write articles. This can create more content, and remember to come back to see what's new.
External connection just submit your site to the appropriate site, they connect to you, tell them that their visitors will return. But don't spend too much time in this convenient, if you have good original content, they will find you, and even to you. Remember, if the "content is King", then the "connection." Reciprocal links, link farms, away from Ghost connections, and any other unnatural connection. They will not hurt you, but Google tracks all of this: when you get a connection, how long to get a connection, who now who comes to your site, and where do you live, what's for breakfast, and so on. (A little joke, but it's like that)