Information architecture is a new profession that's gaining recognition. Like GoTo Auctions, many companies create the title only after someone on staff discovers that an information architect is needed. Others know that's what they need and specifically recruit for that position. Complex e-commerce sites with many different products are especially likely to recognize the value of information architecture. A related position called user interface designer or user interaction designer performs a similar function but at a less strategic level.
Information architecture tends to be concerned with the whole, the structure of a site.
It's like the difference between the person who designed the supermarket and the person who designed the checkout line bar code reader. There is no formal training for information architects yet. Some, including Link, come from editorial backgrounds. Link says an editorial design job is the perfect training ground for an information architect's role. When designing a newspaper page, she points out, you put the most important story at the top.