We don't allow any developer, related developer accounts, or their affiliates to submit multiple extensions that provide duplicate experiences or functionality on the Chrome Web Store. Extensions should provide value to users through the creation of unique content or services.
Developers must not attempt to manipulate the placement of any extensions in the Chrome Web Store. This includes, but is not limited to, inflating product ratings, reviews, or install counts by illegitimate means, such as fraudulent or incentivized downloads, reviews and ratings.
We do not allow extensions that abuse, or are associated with abuse, of notifications by sending spam, ads, promotions, phishing attempts, or unwanted messages that harm the user's browsing experience.
We don't allow extensions that send messages on behalf of the user without giving the user the ability to confirm the content and intended recipients.
In addition to these requirements, all extensions must comply with Google's Webmaster Quality Guidelines.
For additional information about the spam policy, see the Spam FAQ.