Actually people were exploiting the DM for tokens, and XP/AA's long before the "play as yourself" came into effect. Although it wasn't until recently when word got out how to do it and everyone started doing it! And of course, once it becomes an extremely well known and popular exploit, then SOE fixes it. (the exploit has been around since DM was released, and wasn't fixed until about a few months ago).
Remember the patch that made it so the Effect Mods that decreased a mobs HP didnt decrease it so much anymore? Thats because people were using one of the free Avatars that had an AoE Attack that would hit an UNLIMITED amount of targets. People would zone in, 1 shot 1000+ mobs stacked on eachother, zone out, repeat. Gaining multiple levels/aa's instantly. You could level once or twice, however long it took you to load.
I'm glad this got fixed. But it sad that it took so long, allowing so many people to create new toons, and be max lvl with max aa's and hundreds of thousands of marks in a matter of an hour or two. This exploit (specially for gaining marks) also quickly flood hundreds of thousands of plat into the game from people gaining 1000+ marks in 2-5 seconds, buying the crates/items, and selling to an NPC.