We have a HUGE outlet mall near our university. Now, granted, my friends and I aren't really the best shoppers--we're more of the nerdy, stay-at-home-with-movies-and-wine type--but we do enjoy it on a beautiful weekday when none of us has classes and the place is relatively deserted.
And we actually spend less money at the outlets than we do at a regular mall.
We actually get good bargains at our outlets. First of all, most of the outlets have amazing sales on products another branch of that store may be selling at full price still; there's always a 75% off rack at the outlet stores, versus the no-sales-racks policy at some of the regular mall stores. In fact, just a couple of weekends ago, I stopped at Charlotte Russe and got a shirt for $6 and a pair of shorts for $5, both on clearance. Then when I stopped at the regular mall to pick up a ring I'd had resized, I noticed that the non-outlet Charlotte Russe was selling the same stuff...in more colors, maybe, but still at full price!
Secondly, because there are so many stores and we kinda suck at shopping, we generally talk beforehand about the places we really want to hit, and that's where we spend our money...but we don't spend much time in other stores. Maybe it's because we just want to see everything, but most stores we spend no more than 2 minutes in, just walking around and looking. Whereas in a regular mall, which is smaller, we're more likely to stay longer and be tempted to try stuff on, then buy it.
Thirdly, I think because there are so many stores so close together, the outlet stores realize that they're surrounded by more competition, so they tend to be more competitive. I can't tell you how many times we've gone in to outlet stores and had sales people adjust their sales for us, just to make a sale. For example, we went in to a clothing store once where it was supposed to be "buy two, get one free" on jeans, but the girl at the counter was like, "I'll make it buy ONE get one free for you, if you promise to buy at least 2 pairs!" So instead of getting one free pair of jeans for every two pairs we bought, we got two free pairs of jeans for every two we bought.
My mother also managed to get a Coach purse for my sister for $150 instead of $250, all because she slyly mentioned that she could always sidle down to Juicy, Guess, or Fossil to check out THEIR purses. I've NEVER had that kind of stuff happen to me at a regular mall, where stores have less competition and you're likely to only find one store of each "type" (ie, you'd only have Fossil, Coach, Juicy Couture, or Guess in our regular malls, not all 4).
Also, because there ARE so many different stores, we can pick and choose outfit pieces from a ton of different places, rather than settling for something that matches but we may not like as much from the same place. For example, we've gotten undies at one place, shoes at another, shorts and a blouse at a third, and picked out the jewelry at a fourth place. In the regular mall, when we're "building outfits," we often have to settle for what's in one store even if we don't like it as much, all because there aren't as many stores with stuff that might "match."
However, it's worth noting that we do NOT drive far to go shopping there. Our university is literally 10 minutes away, so we don't end up with that mentality. I've warned my sister about it, though, because she wants to drive up here (over an hour both ways), and she's a shopaholic to begin with!
That's just my experience, of course. I'm sure other people have outlet malls that overcharge, and that just sucks. :/