Many of the YC startups listed there have had more than seed funding. They just didn't announce it. Two others haven't bothered to raise money because they were already profitable and didn't want the distraction.
Four were (ramen) profitable by Demo Day this summer. Two of those did take money from investors. The other two might still at some point. All four have had offers.
Also note that for several of these (like Frogmetrics, Picwing, and others), pageviews aren't the best metric of "success" because the website isn't the product.