The slang phrase used to describe the growing number of online marketplaces that provide selling channels that does not include eBay, the top number one ranked marketplace in terms of traffic.
In a general sense of the phrase, because eBay has long been ranked as the top selling channel, all others can be called an alternative to it, much in the same way that people tend to refer to any operating system that is not Microsoft Windows, an alternative operating system.
The term eBay alternative is used when describing a non-eBay Web site that offers services similar to eBay, such as auction and fixed price listings and hosted storefronts, but it is also used when describing a marketplace that offers classified ads and other types of selling services.
The sites that make up the vast and constantly growing list of eBay alternatives are loosely grouped into two categories; those that can offer online sellers a high Web site traffic number (which equates to a larger number of sales) and those that are smaller and serve fewer numbers of buyers and sellers on their site. In many instances, when referencing the first group, they may be referred to as viable eBay alternatives.
The larger alternative sites are generally more firmly established marketplaces that are corporate-owned. These channels, like eBay, are more expensive than other, smaller, alternatives to use as a selling platform. However, they are highly trafficked sites with millions to tens of millions of visitors each month, making them more appealing to larger sellers and merchants. Some sellers will use these alternative channels in connection with their eBay business. These types of channels are used by B2C (business-to-consumer) and C2C (consumer-to-consumer) sellers and merchants. While not a complete list, some examples of this type of eBay alternative includes; Amazon, craigslist, Etsy, Kijiji, PriceGrabber (storefronts) and others.
Some people, however, do not consider the corporate-owned bigger marketplaces when using the phrase eBay alternative, despite the fact that these are a more viable and financially stable (or financially backed) alternative to eBay for online sellers and merchants.
For many, the phrase eBay alternative is used in reference only to the many smaller online auction sites and niche-focused marketplaces. These sites usually promote their services specifically as an alternative to eBay, with lower and fewer fees and policies, and many were started by ex-eBay sellers who opposed fee increases and corporate policy changes at eBay. These sites typically bring in traffic ranging from a thousand or so monthly visitors up to hundreds of thousands of visitors monthly. They rely on attracting sellers who take issue with fee and policy changes on eBay and the larger alternative sites.
This type of eBay alternative tends to appeal mostly to the online sellers who do not sell online full-time; casual, lower-volume, and hobby sellers looking for a community-oriented marketplace to buy, sell and trade online. Few of these sites use proprietary backend systems, but rather are created using an off-the-shelf software product or script (like PHP Pro Bid, Active Auction Pro, or rwAuction Pro). While not a complete list, some examples of this type of eBay alternative includes Webidz, PlunderHere, Blujay, iOffer and many other niche category and auction-based sites. These types of marketplaces are used most frequently for C2C sales.
See Online Auction Abbreviations in the Quick Reference section of Webopedia.