The fee structure is both a filter against superfluous submissions and a revenue generator. Typically, the fee covers an annual subscription for one webpage, which will automatically be catalogued on a regular basis. However, some companies are experimenting with non-subscription based fee structures where purchased listings are displayed permanently. A per-click fee may also apply. Each search engine is different. Some sites allow only paid inclusion, although these have had little success. More frequently, many search engines, like Yahoo!, mix paid inclusion (per-page and per-click fee) with results from web crawling. Others, like Google (and as of 2006, Ask.com), do not let webmasters pay to be in their search engine listing (advertisements are shown separately and labeled as such).
Email Marketing: Email marketing is still one of the most effective digital marketing channels. Many people confuse email marketing with spam email messages we all receive per day, but that’s not what email marketing is all about. Email marketing is the medium to get in touch with your potential customers or the people interested in your brand. Many digital marketers use all other digital marketing channels to add leads to their email lists and then, through email marketing, they create customer acquisition funnels to turn those leads into customers.