Email scraper allows you to crawl niche realted websites it generates through Bing based on your search terms for email addresses. It allows you to generate massive email lists without the need for proxies. How you use these email lists is up to you. However as it is illegal to email scraped/harvested emails under the CAN-SPAM act I would strongly enourage you to use these lists for targetting users on adverising platforms such as Facebook who allow you to load in an email list and target users based on their email address.
If you own a body building forum and you want to find the email addresses of other people who might be interested in body building you would simply enter something like "body building forum" into the Email Scraper it will then serch the Bing search engine for websites related to "body building forum". Once it has a list of these websites it will crawl each page on each of these websites for any email addresses it can find.
Email Scraper allows you to build huge email lists without the need for proxies like a lot of other email scraping software. You can then target people by email address on advertising platforms that you may not typically reach if they haven't shown an interest in that niche while using that platform/social network.