Improving Your Deck
A standard deck has only one memory. (holds 10 Memory Units (MU), or about ten programs), has a Speed of 0, and a data wall Strength of 2. While this isn't gonna mean much to you now, by the time you get to Net Combat and Designing Data Fortresses, you're going to want to know how to boost your deck as far as you can go.
Memory: For an additional 5,000eb, you can purchase an additional memory for your deck. This improves your program power to 20 MU, double its stock size.
Speed: For an additional 2,000eb, you can increase your deck's speed by one level, up to a ceiling of 5. This can be a lifesaver, as deck speed determines who moves first in a Netrunner combat. And in this game, last is dead.
Data Walls: For an additional 1,000eb, you can increase your deck's data wall protection by one level, up to a ceiling of 10. Data walls are important; they are the "armor" of the deck, resisting attacks from anti-system programs.
And then there are options...