So, I'm looking at my Blood Angels collection and thinking about Allies. I'm thinking "I could get a couple of Chimeras, some IG grunts, some badass tank to sit back and shoot at things, and boom, there's an excellent fire support and objective holding section to my army, allowing me to focus on all the air-dropping Blood Angels stuff that I really enjoy."
I could do the same thing with my Tau, acquiring some Eldar stuff to support them (though I'm less likely to do this, as I don't think Eldar+Tau matchup adds to the Tau without just being better than them in the same way that the Imperial Guard adds excellent fire support to the melee-focused Blood Angels).
And then I realized that GW has me thinking about buying into another army. In a minor way - I'm not likely to focus on anything other than my Blood Angels and my Tau, ever - but in a way that will wring money from this stone, nevertheless.
Well played, good sirs. Well played.