To the people saying no snippets, I agree from a fans point of view. But you need to think about the wider audience. For people who aren't fans of Katy, they might not be inclined to buy the album based on the single or the promo songs. Putting up even 15-30 seconds of each song isn't going to harm the sales in any way and it will give non-fans a sense of what the album will be like. (You have to admit all the 4 songs we've heard so far are pretty different from each-other).
