If you are a locksmith or a pizza shop mobile search ads which drive conversion oriented calls are highly valuable. However for businesses with more complex sales funnels desktop visitors have a substantially higher visitor value than mobile phone users. In August of 2016 TripAdvisor executives stated their visitor values on desktop and tablet devices were similar, but cell phone visitors were only worth 30% to 1/3 as much. Smaller businesses likely see a deeper click value discount on smart phones and other small mobile devices where typing (and thus converting) is hard to do.
Search engines may penalize sites they discover using black or grey hat methods, either by reducing their rankings or eliminating their listings from their databases altogether. Such penalties can be applied either automatically by the search engines' algorithms, or by a manual site review. One example was the February 2006 Google removal of both BMW Germany and Ricoh Germany for use of deceptive practices.[54] Both companies, however, quickly apologized, fixed the offending pages, and were restored to Google's search engine results page.[55]
The caveat in all of this is that, in one way or another, most of the data and the rules governing what ranks and what doesn't (often on a week-to-week basis) comes from Google. If you know where to find and how to use the free and freemium tools Google provides under the surface—AdWords, Google Analytics, and Google Search Console being the big three—you can do all of this manually. Much of the data that the ongoing position monitoring, keyword research, and crawler tools provide is extracted in one form or another from Google itself. Doing it yourself is a disjointed, meticulous process, but you can piece together all the SEO data you need to come up with an optimization strategy should you be so inclined.

Website-specific crawlers, or software that crawls one particular website at a time, are great for analyzing your own website's SEO strengths and weaknesses; they're arguably even more useful for scoping out the competition's. Website crawlers analyze a website's URL, link structure, images, CSS scripting, associated apps, and third-party services to evaluate SEO. Not unlike how a website monitoring tool scans for a webpage's overall "health," website crawlers can identify factors such as broken links and errors, website lag, and content or metadata with low keyword density and SEO value, while mapping a website's architecture. Website crawlers can help your business improve website user experience (UX) while identifying key areas of improvement to help pages rank better. DeepCrawl is, by far, the most granular and detailed website crawler in this roundup, although Ahrefs and Majestic also provide comprehensive domain crawling and website optimization recommendations. Another major crawler we didn't test is Screaming Frog, which we'll soon discuss in the section called "The Enterprise Tier."
Webmasters and content providers began optimizing websites for search engines in the mid-1990s, as the first search engines were cataloging the early Web. Initially, all webmasters only needed to submit the address of a page, or URL, to the various engines which would send a "spider" to "crawl" that page, extract links to other pages from it, and return information found on the page to be indexed.[5] The process involves a search engine spider downloading a page and storing it on the search engine's own server. A second program, known as an indexer, extracts information about the page, such as the words it contains, where they are located, and any weight for specific words, as well as all links the page contains. All of this information is then placed into a scheduler for crawling at a later date.
Ever heard of Maslow's hierarchy of needs? It's a theory of psychology that prioritizes the most fundamental human needs (like air, water, and physical safety) over more advanced needs (like esteem and social belonging). The theory is that you can't achieve the needs at the top without ensuring the more fundamental needs are met first. Love doesn't matter if you don't have food.