1. A network device, comprising: a transceiver to send and receive data over a network; and a processor that is operative to perform actions, comprising: receiving an advertisement with Ad keywords associated with the advertisement; segmenting content from the advertisement to select a set of phrases for the advertisement; generating a query list having a plurality of queries based on the selected set of phrases; for each query within the query list, performing an internet web search to identify a set of search result snippets; analyzing the set of search result snippets to select another set of phrases denoted as a query expansion feature set for each query; ranking the other set of phrases within each query expansion feature set and a frequency over all query expansion feature sets; selecting from the ranked other set of phrases a subset of phrases as an ad expanded feature set that is combined with the Ad keywords associated with the advertisement to generate an expanded Ad index; and when receiving a request to provide to a client device other content for display, selecting an advertisement from a plurality of advertisements, including the received advertisement, based on the expanded Ad index.