类似项目推荐的多相关性排名模型

Promoted Listings Standard (PLS) helps sellers’ items stand out among billions of listings on eBay. eBay offers several ways to surface PLS listings. One way is placing those items on the search result page at a higher rank, with a “sponsored” badge; another way is recommended by our PLS item recommendation engines on View Item Page. Such PLS items’ high surface rate costs the seller an additional ad rate fee.This helps to increase the likelihood of a sale while staying seller-friendly, as the seller pays only upon sale of the item.

Promoted Listings Standard (PLS) 帮助卖家的物品在 eBay 上数十亿条物品中脱颖而出。 eBay 提供多种方式来展示 PLS 的物品。一种方式是将这些物品放在搜索结果页的较高位置，并附上 "赞助 "徽章；另一种方式是由我们的PLS物品推荐引擎在 "查看物品页 "上推荐。这种PLS物品的高浮现率需要卖家支付额外的广告费。这有助于提高销售的可能性，同时保持对卖家的友好，因为卖家只在物品销售时付款。

This essay focuses on the latter surface way of PLS items, that is the recommendation engines which help users engage with our PLS content, and help us optimally display the items in our uniquely vast and diverse marketplace. One of the recommendations is to recommend similar sponsored items, which is called Promoted Listing SIM (i.e. PLSIM1). The typical user journey for the PLSIM consists of the following steps:

这篇文章主要讨论PLS项目的后一种表面方式，也就是帮助用户参与我们的PLS内容的推荐引擎，并帮助我们在我们独特的巨大和多样化的市场中优化显示项目。其中一个建议是推荐类似的赞助项目，这被称为Promoted Listing SIM（即PLSIM1）。PLSIM的典型用户旅程包括以下步骤。

The user searches for an item.
用户搜索一个项目。
Clicks on a result in the search result page, landing on a View Item (VI) page for a listed item, which we refer to as the seed item.
点击搜索结果页面中的一个结果，登陆到一个列出的项目的查看项目（VI）页面，我们把它称为种子项目。
Scrolls down the VI page, and sees recommended items in PLSIM.
向下滚动VI页面，看到PLSIM中的推荐项目。
Subsequently clicks on an item recommendation and arrives at a new VI page to see the main listing details to either take action (watch, add to cart, buy it now, and more) or check out another, new set of recommended items.
随后点击一个项目推荐，到达一个新的VI页面，看到主要的清单细节，以便采取行动（观看、添加到购物车、立即购买等）或查看另一个新的推荐项目。

In turn, from a machine-learning perspective, our PLSIM engine2 has three stages:

反过来，从机器学习的角度来看，我们的PLSIM引擎2有三个阶段。

It retri...