Minekey is another online behavioral targeting company enjoying a boom of interest in such wares, because it makes it easier for publishers to push content more efficiently to visitors.

The Sunnyvale, Calif. company is already helping sites to grow traffic — but it also raises questions about privacy.

The company is not new, but we haven’t mentioned it before. Today, it has introduced improvements to its widget that publishers can embed in their sites. The widgets provide information to users that it finds relevant to them based on their past surfing habits.

It uses a cookie to record individual user’s browsing behavior on sites using its widget.

Like Aggregate Knowledge and other competitors, Minekey also analyzes the collective behavior of visitors to all web sites using its widget in order to discover trends in tastes. It pairs this personal and aggregated information with the content on the page a user is on to predict what a user will be most interested in.

Web publishers can choose to only run articles from their own sites, or include RSS feeds from other sites they want to readers to see.

The company has been reporting the widget has increased net clickthrough rates to relevant articles by around ten percent on average for over 1000 sites already using the service.

The improvements are focused on making Minekey friendlier to publishers. It is minimizing its branding on the widget, letting publishers choose a wider range of colors so as to match existing sites’ themes, and rolling out improvements to the traffic-analysis information it provides.

Aggregate Knowledge and Wunderloop (coverage of both here) also help companies advertise products more effectively on sites — as does Loomia.

Behavioral targeting is controversial because users are often tracked without their explicit knowledge or consent. Many companies use cookies to track individual behavior, chief executive Delip Andra points out. Minekey lets users edit their “history,” or list of visited article pages, to monitor what Minekey knows, and to improve their recommendations — similar to Google’s web history. However, Google is increasingly under fire these days for not respecting its users’ privacy and is openly shying away from behavioral targeting for advertising.

Minekey has raised $3 million from New Enterprise Associates.