How bad can the economy be if people are buying acai?, Surely you've heard of acai, even if you're not sure how to pronounce the name. (It's ah-sigh-EE.) The little purple berries have been touted for more healthful qualities than you'd think a simple berry could bear. Who'd have believed that this modest product of Brazil's Amazon rain forest could do everything from speed weight loss to correct sexual dysfunction -- while bolstering your immune system, too? A lot of people. According to Spins, a market research and consulting firm for the natural products industry, Americans spent more than $108 million on acai products in the 52 weeks ending Feb. 21, up from just over $62 million the year before. That's a lot of berries. But are buyers getting their money's worth? That depends on what they expect.