MongoDB can rapidly scale out to capture really large data sets, sort them, report on them, analyze them. Merriman freely concedes that No.SQL systems are not necessarily good at capturing long-lived, complex transactions. Theyre good at archival. They’re good at event logging, he noted, then performing analysis on the large data set to learn things from a disparate set of events. This facility is great, he said, and he thinks the future for No.SCV for Silicon Valley looks bright as well.”]
Source: https://www.darkreading.com/database-security/10gen-raises-6-5-million-for-mongodb