Medicine: Lexapro goes generic

Apparently Lexapro was the number 2 seller behind Zoloft, which is quasi-shocking to me. I'm wondering if this actually represents the number of prescriptions for escitalopram versus sertraline, or Lexapro versus Zoloft, i.e. what "brand name" drugs are being sold the most. I'd imagine that generic sertraline (Zoloft) and citalopram (Celexa, and the racemic mixture of Lexapro), would blow the more-expensive and probably-no-better-tolerated Lexapro out of the water.

For those not in the know, among the class of drugs wrongfully called SSRIs, since the fact that they are SSRIs probably has nothing to do with their efficacy, sertraline and citalopram are the two antidepressants that play most nicely with other drugs, which of course becomes important for folks taking 20 other meds.