If you've never been on Product Hunt before, it's like a daily Reddit feed for new products. Products get submitted to the community and they're voted on. Each day products are stacked in descending order based on how many votes they've had. Ranking at the top of the daily list can result in thousands of conversion-focused traffic to your site, just as the creator of Nomad List found out.
Often the line between pay per click advertising and paid inclusion is debatable. Some have lobbied for any paid listings to be labeled as an advertisement, while defenders insist they are not actually ads since the webmasters do not control the content of the listing, its ranking, or even whether it is shown to any users. Another advantage of paid inclusion is that it allows site owners to specify particular schedules for crawling pages. In the general case, one has no control as to when their page will be crawled or added to a search engine index. Paid inclusion proves to be particularly useful for cases where pages are dynamically generated and frequently modified.
Because so few ordinary users (38% according to Pew Research Center) realized that many of the highest placed "results" on search engine results pages (SERPs) were ads, the search engine optimization industry began to distinguish between ads and natural results. The perspective among general users was that all results were, in fact, "results." So the qualifier "organic" was invented to distinguish non-ad search results from ads.
Pay Per Click (PPC) advertising is the most common form of paid SEM. PPC ads are the ones you see at the top of your Google search with the word “ad” written discreetly next to the link. Search engines such as Google sell keywords to the highest bidder. One of the nice things about this form of advertising is that – as the name suggests – you only pay for the ad when someone actually clicks on it.
Well, yes and no. Sure, you can get hit with an algorithm change or penalty that destroys all your traffic. However, if you have good people who know what they are doing, this is not likely to happen, and if it does, it is easy (in most cases) to get your visits back. Panda and Penguin are another story, but if you get hit by those it is typically not accidental.