QOTD: Product Reviews

When companies send their products to bloggers to review (sometimes offering free giveaways to readers), do they expect a positive review? Do bloggists ever struggle with the dilemma of hating a product? And why are we so obsessed with trials and reviews anyway, especially for things under $15? Are we afraid to try new things? Or just loathe to have that half-eaten package left in the fridge to rot over the next week or two as no one jumps to finish it off?