@ Alex: I bet raiding would have been useful in 0.9a, but I did not know transponder-off eliminated suspicion at the time. Because of that, I avoided Black Market like the plague, thus, no cheap marines. After learning of that change recently, I shop at Black Market all of the time to avoid tariffs. In fact, a reason why Commerce on my colony is useless for buying and selling stuff is because of 1) tariffs and 2) pop-up pirate or pather bases. Even without tariffs, some pop-up bases can sell stuff cheaper than what I can draw from my colony resources, especially personnel. Anytime I have junk stored at my colony to sell (or to top off on crew and marines), I can wait (or not) for a pirate base to spawn near my colony to target it, then I can bring my junk (except blueprints), sell it to pirates, raid them for stuff, then kill them. Pirates are more like pushy travelling salesmen.
Last night, built a colony early (Oct or Nov 206) in a system next to a pirate base. I considered saving that base until there was a bounty posted and raid that base repeatedly for freebies in the meantime, maybe see if it decivilizes. In the end, I decided to destroy it before that base grew from a one-section wimp that my modest fleet of destroyers could handle to a full-sectioned tier 1 station that would be too hard to destroy.
I bought a Colossus 3 because my fleet needs some cargo capacity, and I wanted to boost my raiding power a bit in case I bring fewer marines. (My income is not very high yet.) I think my current game is the first one where raiding is a significant early-game income source. It would yield the most income if I am willing to sell the blueprints I steal, but I decide to either learn or hoard them instead.