51. Started at Duke University in 1979, _____ was a set of interconnected computers devoted to storing information on specific topics.
52. Modifying an Apple iPhone's operating system is called _____ the phone.
53. Intra-community interaction among members of a virtual community is called _____.
54. Modifying an Android operating system is called _____ the phone.
55. Abstract communities based on the connections between opinions and contributions of community members are called _____ social media.
56. _____ software is developed by a community of programmers who make the software available for download at no cost.
57. One rough measure of _____—a Web site’s ability to keep visitors on the site and attract repeat visitors—is how long each user spends at a Web site.
58. An early attempt to monetize social networking by charging visitors a fee for a specific service was the _____ site.
59. _____ refers to the conversion of existing regular site visitors seeking free information or services into fee-paying subscribers or purchasers of services.
60. _____ is the practice of lending very small amounts of money to people who are starting or operating small businesses, especially in developing countries.