http://forums.dirtybomb.com/discussion/35857/ranked-season-2-update-notes/p1?new=1

Earn Ranked Points to buy Ranked Season 2 Cases for 1000 points each.

You can get your hands on Ranked points in three ways:

Log in Now

To celebrate the beginning of the season, log in within the next two weeks for 500 bonus Ranked Points to get you on your way!

GIVEAWAY DURATION!
London (GMT, UTC): 14:00 Wednesday, March 1 - 14:00 Wednesday, March 15
Los Angeles (PST, UTC-8): 6:00 AM Wednesday, March 1 - 7:00 AM Wednesday, March 15
Sydney (AEST+1, UTC+11): 1:00 AM Thursday, March 2 - 1:00 AM Thursday, March 16

Playing Ranked Matches

Earn points for every match you play. The better your team does, the more points you'll earn as you work through the season.

Team Results
Win: 50
Draw: 30
Loss: 10

Placement

When Season 2 ends, you'll earn points for the highest Rank you've achieved through the Season.

These range from 100 points for Bronze Recruit, to 4500 for Elite Operative. All possible rewards can be found in the 'Ranked' tab in your Profile.