One review site that provides valuable insights is G2 Crowd. They score products and vendors based on ratings and reviews gathered from the user community, as well as data aggregated from online sources and social networks. They apply a unique, patent-pending algorithm to this data to calculate the customer satisfaction and market presence scores in real time.
A lead magnet (a.k.a. an optin bribe) is something amazing that you give away for free in exchange for an email address. This doesn’t have to cost you anything to create; most lead magnets are digital materials like PDFs, MP3 audio files, or videos that you can create yourself at minimal or no cost. It can be absolutely anything you want, so long as it provides value to your visitors for free.