Those looking at picking up the PC version of Batman: Arkham Asylum should strongly consider doing so before March 1st.
Those who purchase Batman: Arkham Asylum on Games on Demand through Games for Windows – LIVE will get 75% off their purchase. The deal is available in all regions that support Games on Demand, so no worries about this being US only or something of the sort.
Microsoft plans on continuing big sales all throughout March on titles available on Games for Windows Live, so keep an eye out.
(Source: Major Nelson’s Blog)