In large part, you are correct. Buy in advance (on rumour?), and sell on news. There's only 3 reasons I'd be selling to them: Either to recoup my investment and ride the freebies, to exit entirely and take my profits, or because I'm bailing out of what appears to me to be a losing or stalled position.
If I'm selling to recoup my investment, but continue to ride freebies, obviously, I still see upside potential, but simply desire to move into other positions too.
If I exit entirely (though more than once, a stock has continued to rise), more often than not, I found the peak, and exited close to it.
As a side note, I tend to play Mid to Long on most stocks, though I do daytrade occasionally. Given that, those who read this must bear in mind, my suggestions are bent towards that design. I prefer plays I can walk away from for more than 10 minutes and not worry about tanking on me.
to make a million bucks over night" 
