It seems to be a common phenomena. Before I bought my Explorer I knew I was looking for a SUV in general. I was keeping an eye out for 6th gen Explorers and rarely saw one. I live in an apartment facing a highway in DFW, with all the cars I see you'd think I'd see a ton of them, but I didn't.
After I bought mine, I see them everywhere now. I see tons of STs as well.
Something similar happened when I was a kid. My parents bought a used 1990 Chevy Corsica in the mid-90s. I'd never even heard of a Chevy Corsica before that. After that I saw them everywhere.