Greed

Economy is a hugely important resource in Netrunner, but not as important as the resource of time. I don't mean that in the specific sense of credits vs clicks but rather that you can have all the money in the world but if your opponent is on 6 agenda points, you're in a whole heap of trouble still.

Often, you won't need stacks of money to win in Netrunner. Runners and corps alike will frequently be guilty of hoarding their credits when their goal should be breaking through servers at the lowest possible cost or defending your servers at the best possible cost to benefit ratio. For instance, there's a reason why most successful corp decks at the moment play with a significant proportion of cheap, ETR ICE. It's because it's cheap, and it ends the run (facetious alert). A corp cannot lock a server down forever; any runner worth their salt is going to have a solution available for almost every likely instance. What they can do is force the runner to spend valuable time and credits getting icebreaker cards out into play while better solidifying their own position. This is why big ICE decks are inherently problematic. It has cost the corp a lot of money and therefore time to rez that Janus or Curtain Wall which will likely be punished with cards like Femme and Emergency Shutdown.

Runners also should build their decks around efficient breakers. Some breakers look incredibly cost effective on paper, but the tempo hit that ensues from getting the capital together to play said breaker may add further time based costs.

Don't just save money for a rainy day, use it while the sun shines and capitalise on any and all weakness.

There is one important exception to this rule, when playing (or playing against) a tag and bag deck, greed is good. Try and stay in a stronger economic position so you can keep yourself safe as runner or find the means to tag as corp. Economy suddenly becomes the whole song and dance in this instance.