Valve will reward people who pre-order Left 4 Dead 2 with early access to a multiplayer demo.
Pre-orders can be registered via Steam for PC or at "participating retailers", Valve spokesperson Doug Lombardi told OXM.
There's no specific date for the multiplayer demo, but it will arrive before L4D2's launch on 17th November. That's a Tuesday, incidentally, which means UK retailers are likely to stock the game from 20th November - a Friday.
All other PC and Xbox 360 owners will be able to play the multiplayer demo at a later date.
Valve recently told Eurogamer that pre-orders for Left 4 Dead 2 are twice that of the original game over the same period of time, despite threats of boycott by angry fans who thought Valve would forego promised DLC in favour a quick sequel.
Head over to our freshly-minted hands-on impressions of Left 4 Dead 2 to see how the sequel is shaping up.