LinkedIn LinkedIn is a social networking service that's been around for a long time. It provides services like the ability to recommend and receive work recommendations, and it has a collection of user interest groups that, if used properly, can garner interesting leads and potential opportunities. The core LinkedIn service is free. But LinkedIn offers three levels of subscription, offering some degree of upgrade over the basic account. The most expensive, costing a whopping $499.95 per month, allows you to send 50 messages to people you're not linked to every month, while your searches can pull up 700 profiles at a time. The two other packages, Business ($24.95 per month) and LinkedIn's recommended choice Business Plus ($49.95 per month). Therefore you get three or ten direct messages, 300 or 500 profile results per search, and the organize profiles feature allows the creation of five or 25 folders.