1. A system, comprising: at least one processor; a memory having instructions executable by the at least one processor to cause the system to carry out operations comprising: receiving user-generated content from one or more web sites, wherein the user-generated content includes one or more reviews of at least one product or service; storing the user-generated content including the one or more reviews in an encoding format suitable for incorporation within a web page; based on information indicating that a specified criterion relating to a first one of the one or more reviews is met, generating an alert in a digital format encoding the specified criterion; using an electronic messaging protocol to provide the alert to a provider of the at least one product or service; subsequent to using the electronic messaging protocol to provide the alert, receiving, from a representative of the provider of the at least one product or service, a response to the first review; subsequent to receiving the response, storing the response in the encoding format; subsequent to receiving the response, generating an invitation, for a reviewer that corresponds to the first review, in the digital format encoding invitation information inviting the reviewer to reply to the response; upon generating, providing the invitation to the reviewer; and based on storing the response in the encoding format, instructing a host computer device for a first one of the one or more web sites to incorporate, into source code of a web page of the first web site, the response and an indicator indicating that the response is an official response authorized by the provider, and further instructing the host computer device to display the web page including the response from the representative and the indicator.