I ran across a resistor network component, but I can't find any basic electronics tutorials that use these in practice. What is something like this used for?
Imagine you have an IC (microcontroller, shift register etc.) with 10 outputs, each one requiring an additional pull-up or pull-down registers. Or image you have 10 LEDs that need to be conntected to Vcc or ground via a resister.
In such cases the resister network comes in handy. You only need to use one or two resistor networks instead of 10 individual resistors. It's helpful on a breadboard to reduce the number of wires. And it's helpful on a production board as it reduced the number of components that need to be placed.
Two advantages resistor networks offer over discrete resistors in analog applications are better thermal tracking and availability of precision ratios. Because the resistance network elements share a common substrate, they are subject to more equal thermal effects.
Networks are available in precision ratios. To achieve this with discretes, one must use either higher precision resistors or measure resistor pairs to obtain the required ratio precision.
They area available in different styles also. 1 common pin with all others in series to it (bussed). One resistor across 2 pins only (isolated). Single inline package (as shown in the question), Dual inline package (DIP, like an IC).
With so many designs going to surface mount, I would suspect networked parts are used less these days.