Someone knows a guy in Mexico City who runs secret bookstores out of apartments and became one of the most prolific collectors in the Spanish-speaking world through pure strategy: he kept a detailed map of every minor lawyer, politician, and academic in town. When they died, he showed up at the funeral to console the widow and ask if he could peek at their collection first. It's the kind of ruthless networking that makes normal networking look quaint. Map the target, wait for mortality, strike at maximum emotional vulnerability, walk away with rare books.