Like some other f2p games there are Daily prizes - u log in every day and play, lets say 5-10 games to get a daily (so its not to easy to get them but also not hard) - it lasts for 7 days - if u miss 1 day it resets!
Also for hardcore players if day do all daily prizes in hole month they should get something - maybe add some loadout card like obsidian with nice skin and weapon and give it for use ( 7 days) .
1st day - 1 case
2nd day - 500c
3rd day - 2 cases
4th day- 1000c
5th day- 3 cases
6th day- 1500c +1 case
7th day- 2000c + 2 cases
^^ IF u get all dailyes u can earn around 5k credits and few cases
[OR] Maybe if get some other stuff in game in future ( different cases, cosmetics, boosts etc) they can add those in.
Exmple for future - maybe
1st day - 1 case
2nd day - 500c
3rd day - 2 cases
4th day- 1000c
5th day- 3 cases + 35% EXP Boost ( for 24h)
6th day- 1500c +1 case + 35% Credits Boost (for 24h)
7th day- 2000c + Hat (for 3 days) + 1 “premium” case
This could keep players coming back every day and keep game going and fun 
Edit = lowerd the credits cuz of option of to quickly earning new mercs.
Also ty for feedback!