OneRiot’s PulseRank technology – PageRank for the realtime web – gives a high rank to new, fresh content based on the social pulse it’s generating right now.
There is a firehose of realtime information on the social web, and we aim to make sense of that by filtering through the noise and spam to find the most socially-relevant web content related to your search query. We do that with PulseRank, a realtime ranking algorithm that ranks OneRiot search results at search time, to give you the most socially relevant results, right now.
Pulse Rank looks at dozens of factors that give “weight” to certain results. Four key factors to PulseRank are Freshness, Domain Authority, People Authority, and Acceleration.
More info: http://blog.oneriot.com/content/2009/06/oneriot-pulse-rank/