Final answer:
The tactics described, like paying for positive online endorsements or multilevel selling schemes, correspond to 'Viral Marketing'. This form of marketing uses networks to increase brand awareness or sales through processes similar to the spread of viruses.
Step-by-step explanation:
The tactics mentioned in the question such as paying people to say good things about a product online or setting up multilevel selling schemes that reward people for directing their friends to a company's website refer to Viral Marketing. This type of marketing technique is designed to utilize social networks to produce increases in brand awareness or achieve other marketing objectives (such as product sales) through self-replicating viral processes, analogous to the spread of viruses or computer viruses.
Viral marketing may take the form of video clips, interactive Flash games, advergames, ebooks, brandable software, images, text messages, email messages, or web pages. The goal of viral marketing campaigns is to create viral messages that appeal to individuals with high social networking potential (SNP) and that have a high probability of being presented and spread by these individuals and their competitors in their communications with others in a short period.