  In an emerging trend, more and more Internet users search for information
from Community Question and Answer (CQA) websites, as interactive communication
in such websites provides users with a rare feeling of trust. More often than
not, end users look for instant help when they browse the CQA websites for the
best answers. Hence, it is imperative that they should be warned of any
potential commercial campaigns hidden behind the answers. However, existing
research focuses more on the quality of answers and does not meet the above
need. In this paper, we develop a system that automatically analyzes the hidden
patterns of commercial spam and raises alarms instantaneously to end users
whenever a potential commercial campaign is detected. Our detection method
integrates semantic analysis and posters' track records and utilizes the
special features of CQA websites largely different from those in other types of
forums such as microblogs or news reports. Our system is adaptive and
accommodates new evidence uncovered by the detection algorithms over time.
Validated with real-world trace data from a popular Chinese CQA website over a
period of three months, our system shows great potential towards adaptive
online detection of CQA spams.
