WHY-TO-BUY-HERE STRATEGY #1: DEPTH OF INVENTORY.

Depth of inventory is an old and still-powerful concept on the Web. Amazon.com's original selling proposition (before it had competitors who could make the same claim) was that its virtual shelves carried millions more titles than any bricks-and-mortar bookstore. Since software is a product category like books where only a tiny fraction of commercially-available SKUs appear on retail shelves, it's easy to understand the appeal of sites that aggregate huge numbers of products.

Trouble is, depth of inventory by itself is not useful without organization and easy access. (Imagine a vast supermarket with no aisles or departments.) Many first-generation software stores missed this point: Customers could search huge catalogs of line items for specific titles, but anyone who wanted to explore a whole product category--the essence of "shopping"--usually ended up frustrated.

The challenge of making inventory more accessible has been especially urgent for the ZDNet Downloads store (www.zdnet.com/downloads), a site that currently offers thousands of trialware and shareware games, utilities, and productivity titles. Since the Downloads store relies chiefly on income from advertising page views, an important design goal is to encourage visitors to browse deeply and come back often to see what's new. Thus, the Downloads home page is jammed with links to individual product categories, as well as lists of special offers, "hot files," awards, and top-20 selections; lower-level pages repeat this format, showcasing dozens of other links and titles. In addition, ZDNet Downloads sends out a series of daily and weekly e-mail newsletters to a total of 1.2 million people, calling attention to more new products that are available on the site.

Access paths have to lead somewhere, of course, and the ZDNet Downloads store usually brings visitors to lists of downloadable titles organized by category. Since most of these titles are unknown and unbranded, the lists provide capsule information (title, version, brief description, most recent release date, operating system, editorial rating, and total downloads to date), with drill-downs to a longer description, user ratings, the developer's name, and download size--except for price, essentially the same information that customers look for when they buy software instead of downloading trial versions.

ZDNet, One Athenaeum St., Cambridge, Mass. 02142; 617/225-3365.

Another inventory-intensive site, Flashline.com (www.flashline.com), also offers a large collection of little-known titles--in this case, software components that developers buy as application building blocks. The Flashline.com store began chiefly as an online catalog, but it evolved into a more ambitious store when the founders discovered that components customers wanted more than just inventory--they also needed the store's help with issues like quality assurance and complicated multi-user pricing schemes.

As a result, the Flashline.com site has increasingly emphasized value- added services as a part of its relationship with customers. For example, the store now includes an auction-style list of requests for customized components, an industry-wide component registry, a resource library, and a backup archive for components that customers have purchased. Since most individual component developers are too small to offer such services, the Flashline store functions as both an aggregator of services and of products.

Flashline.com, 1300 E. 9th St., Cleveland, Ohio 44114; 216/861-4000.

Still another inventory-intensive site is Bitstream's MyFonts store (www.myfonts.com), which calls itself "the Amazon.com of fonts." MyFonts brings together some 10,000 fonts from a wide range of digital font foundries, and chief technology officer John Collins says Bitstream eventually expects to grow the store's inventory to as many as 50,000 total fonts.

Since fonts are visual objects and the differences between competing versions are usually subtle, font buyers need much more than a standard search engine to explore a font store's choices. To deal with this problem, Bitstream has developed an unusually rich range of search options. The simplest is a search that displays font styles by name (e.g., "schoolbook"). Once a possible font has been chosen, MyFonts customers can try a "show me more fonts like this" option that shows similar designs regardless of name. They can also see all the font styles within a family, and they can search for versions by increasing or decreasing attributes like boldness, width, contrast, or x-height. And if all else fails, the site will analyze a scanned sample of text and will display possible matches.

Bitstream has made the search process even more helpful to font buyers by displaying all available fonts, not just the MyFonts inventory, and by providing links to the foundries that sell fonts Bitstream doesn't offer. Bitstream certainly loses some font sales by helping customers find its competitors, but the obvious tradeoff is that MyFonts is more likely to become a trusted, first-choice destination for hard-core font buyers.

Bitstream, 215 First St., Cambridge, Mass. 02142; 617/520-8401.