Providing content for broadcast by a messaging platform

A system, comprising:

• a computer processor;
• a content promotion module executing on the computer processor and configured to enable the computer processor to:
• assign one or more identifiers of a plurality of identifiers to each of a plurality of content provider accounts of a messaging platform;
• receive promotion criteria from the plurality of content provider accounts;
• prior to receiving an indication that a user of the messaging platform has completed composition of a message:
• receive, from a client computing device, a portion of a message entered by a user of the messaging platform during composition of a message;
• determine one or more identifiers based on the received portion of the message, each identifier corresponding to one or more content provider accounts of the plurality of content provider accounts;
• provide for presentation in an interface of the client computing device;
• receive a user selection of an identifier of the one or more identifiers;
• in response to the user selection of the identifier corresponding to one or more content provider accounts:
• obtain a plurality of content items authored by the one or more content provider accounts, and
• rank the plurality of content items according to one or more ranking criteria, wherein the one or more ranking criteria comprise one or more promotion criteria previously provided by the one or more content providers;
• provide a set of content items for ordered presentation by the client computing device during composition of the message according to the ranking;
• and
• receive, from the client computing device, a selection of a content item of the presented set of content items, wherein the selection is made by the user prior to completing composition of the message;
• receive the indication that the user has completed composition of the message;
• and
• broadcast the message and the selected content item to a plurality of accounts of the messaging platform.

One or more non-transitory computer-readable storage media encoded with instructions that, when executed by one or more computers, cause the one or more computers to perform operations comprising:

• assigning one or more identifiers of a plurality of identifiers to each of a plurality of content provider accounts of a messaging platform;
• receiving promotion criteria from the plurality of content provider accounts;
• prior to receiving an indication that a user of the messaging platform has completed composition of a message:
• receiving, from a client computing device, a portion of a message entered by a user of the messaging platform during composition of a message;
• determining one or more identifiers based on the received portion of the message, each identifier corresponding to one or more content provider accounts of the plurality of content provider accounts;
• providing the one or more identifiers for presentation in an interface of the client computing device;
• receiving a user selection of an identifier of the one or more identifiers;
• in response to the user selection of the identifier corresponding to one or more content provider accounts:
• obtaining a plurality of content items authored by the one or more content provider accounts, and
• ranking the plurality of content items according to one or more ranking criteria, wherein the one or more ranking criteria comprise one or more promotion criteria previously provided by the one or more content providers;
• providing to the client computing device a set of content items for ordered presentation by the client computing device during composition of the message according to the ranking;
• and
• receiving, from the client computing device, a selection of a content item of the presented set of content items, wherein the selection is made by the user prior to completing composition of the message;
• receiving the indication that the user has completed composition of the message;
• and
• broadcasting the message and the selected content item to a plurality of accounts of the messaging platform.