Abstract: Data characterizing a user and a plurality of authors is received at a server and each author having authored user-generated content. The plurality of authors is filtered, using the server, based on data characterizing one or more relationships between the user and each author. Data characterizing the filtered plurality of authors is provided using the server. Related apparatus, systems, techniques, and articles are also described.

Abstract: Recommending one or more geographic locations and one or more temporal locations for a first individual and a second individual to meet includes receiving first data from the first individual and second data from the second individual. The received first data specifies at least the first individual's preferred geographical attributes and preferred temporal attributes. The received second data specifies at least the second individual's preferred geographical attributes and preferred temporal attributes. The received first data, the received second data, and a recommendation engine, one or more recommended geographic locations and one or more recommended temporal locations that satisfy some respective preferred geographical attributes and the respective preferred temporal attributes is determined. The one or more recommended geographical locations and the one or more recommended temporal locations are transmitted to at least one of the first individual and the second individual.

Abstract: Data characterizing an offer for sale of a good or service by a seller is received. The data specifies constraints of the offer. The constraints identify a plurality of groups of potential buyers to which the offer is to be conveyed and characterizes conditions specifying how the offer is to be conveyed to each group. At least one of the groups is determined based on an affinity relationship of the potential buyers in that group to the seller. The terms of the offer may vary between at least two of the plurality of groups based on the relationship. A plurality of formatted offers can be generated. Each formatted offer corresponds to a respective group and to an online marketplace. At least one of the formatted offers can be posted to a respective group according to the conditions. Related apparatus, systems, techniques and articles are also described.