I've been playing with Data Dealer for a while now, and I think it's better, or at least more versatile, than I originally thought. Let's get the obvious out of the way: poison assets (or useless-when-stolen agendas). News Team, Shi.Kyū, et al., all get turned from grief to gold, as 9 is a massive amount of money to get for a single , not to mention the agenda point gain. The problem is, or was, the odds of a corp running them were low enough that you couldn't justify including DD.
Enter Fan Site. Now, even if the corp isn't running said poison, this is still kind of useful. But wait, this has some trouble too, as you need to get the Fan Sites out early enough, and you need to allow the corp to score to even make them worthwhile, and this all assumes you have DD ready to go at some point as well. And finally, Fan Site is out of faction, so you're (in all probability) either importing DD into Shaper or Fan Sites into Criminal. So even with Fan Site, this is still passed over in favor of other econ options.
Finally I asked myself, "What if I actually sacrifice real agendas (i.e. things actually worth points) to this?" Sounds crazy, right? I thought so too at first, until I realized there are times when that is exactly the right thing to do. For example, in a recent game I was way behind; the corp had 6 points scored, and I had only a single 1-point agenda in my score area. He had already burned through his options for fast advance, so what does the corp do? He continually plays agendas into his scoring server, with the hope that I'll eventually run out of econ and be unable to contest them for even a single turn. Desperate, I sell my agenda to the DD, giving me enough credits to contest the server and steal the next agenda. This snowballs, as I now have another agenda to pawn off, and I can just barely afford to break into the server every time he plays an agenda there.
I eventually face-plant into an Aggressive Secretary, and lose the critical breakers I needed to get in to the server. Game over for me? Not so, as the corp has only two cards left in R&D, and, as it would turn out, only one of them was an agenda—the bottom one. It's his final Self-Destruct Chips (corp was playing Cybernetics Division), and he has no way to score it this turn. Even if I have no way to contest the server, it doesn't matter, as I can just sit back and do nothing. When mandatory draw finally rolls around, he's dead.
Was I lucky? Yes. But that's missing the point, as none of this would have been possible without DD. It allowed me to snatch victory from the utter depths of defeat, and turn an impossible situation into merely an improbable one. Sometimes you've just got to cut off the finger to save the hand, and DD lets you do that while keeping you on the edge of your seat in true Criminal style. And it's because of this flexibility that I've really come to appreciate this card for what it is, and what it does. If nothing else, it will probably make for some of the most memorable games of ANR you've ever played. How often does selling off 11 agenda points seem like a good idea?