Mass Effect is a tps/rpg, it doesn't count as RTwP just because you can issue some very limited orders to your two companions, something that most gamers probably don't even use and is not at all necessary in order to complete the game (while it's an important part of the experience in BGs, IWDs and PoE, and you probably will have major problems getting through some battles without using the pause, unless you play on the easiest difficulty). The game plays like the typical third person shooter with covers (only it was way clunkier), which btw was very popular back then thanks to Gears of War and others.
There's a similar feature in The Witcher 2, in which you can hit a button and instead of a pause you get to slow down the game a lot as if you think what to do next, but I wouldn't count it as a RTwP rpg either, because the gameplay is action at its core (just like shooting from 3rd perspective is the core of MEs).
Dragon Age, on the other hand, is definetely RTwP, although I'd argue that it sold so much more than PoE or D:OS, not because RTwP rpgs are that popular but because BioWare was a big name at the time, it was an AAA with a far larger budget than D:OS, PoE or any other new "old school-inspired" rpgs, and also it was released on three platforms simultaneously, and some people who were fans of Mass Effect probably bought it just becase of the brand association, even if they had no idea what RTwP systems were. It was also pushed heavily by EA's marketing at the time, from what I remember. All in all, I'd say that DA:O sold a lot despite being a RTwP rpg, and not thanks to it.
