1. A computer-implemented method comprising: determining a particular language based at least in part on both content of text submitted by a user and a source IP address that is associated with the user; and based on having determined the particular language for the user, presenting, to the user, one or more content items that are associated with the particular language; wherein the content of the text does not expressly state the particular language.
2. The method of claim 1 , wherein determining the particular language comprises: determining a particular market based on a top-level domain of a particular URL; determining whether the text is encoded in ASCII; determining whether only one language is mapped to the particular market in a stored set of market-to-language mappings; and in response to determining that (a) the text is encoded in ASCII and (b) only one language is mapped to the particular market in the stored set of market-to-language mappings, determining that the particular language is the one language that is mapped to the particular market in the stored set of market-to-language mappings.