There could have been a Valentine's tie-in planned months ago (before the leaks happened). Madonna said that the original plan was to release LFL on Valentine's Day, so maybe some suit at Interscope/Live Nation sat down with radio execs last year, asked the stations to push the single on Feb 14, and they just stuck with it. That would explain why there seemed to be no attempt whatsoever by the label to give this a push at radio before that date.
The Valentine's tie-in would also explain the Feb 10 radio add date (same week), even though it was hardly played Tuesday through Friday (that must have been the plan all along). However, no DJ announced LFL as a 'Valentine's' song on Saturday as far as I know. So I'm guessing the Valentine's Day connection would have been a lot stronger had the leaks not happened.