Social media itself is a catch-all term for sites that may provide radically different social actions. For instance, Twitter is a social site designed to let people share short messages or “updates” with others. Facebook, in contrast is a full-blown social networking site that allows for sharing updates, photos, joining events and a variety of other activities.
To avoid undesirable content in the search indexes, webmasters can instruct spiders not to crawl certain files or directories through the standard robots.txt file in the root directory of the domain. Additionally, a page can be explicitly excluded from a search engine's database by using a meta tag specific to robots (usually ). When a search engine visits a site, the robots.txt located in the root directory is the first file crawled. The robots.txt file is then parsed and will instruct the robot as to which pages are not to be crawled. As a search engine crawler may keep a cached copy of this file, it may on occasion crawl pages a webmaster does not wish crawled. Pages typically prevented from being crawled include login specific pages such as shopping carts and user-specific content such as search results from internal searches. In March 2007, Google warned webmasters that they should prevent indexing of internal search results because those pages are considered search spam.
These posts can be one or more of the following: images, photo sets, animated GIFs, video, audio, and text posts. For the users to differentiate the promoted posts to the regular users' posts, the promoted posts have a dollar symbol on the corner. On May 6, 2014, Tumblr announced customization and theming on mobile apps for brands to advertise.
To prevent users from linking to one version of a URL and others linking to a different version (this could split the reputation of that content between the URLs), focus on using and referring to one URL in the structure and internal linking of your pages. If you do find that people are accessing the same content through multiple URLs, setting up a 301 redirect32 from non-preferred URLs to the dominant URL is a good solution for this. You may also use canonical URL or use the rel="canonical"33 link element if you cannot redirect.
Another reason is that if you're using an image as a link, the alt text for that image will be treated similarly to the anchor text of a text link. However, we don't recommend using too many images for links in your site's navigation when text links could serve the same purpose. Lastly, optimizing your image filenames and alt text makes it easier for image search projects like Google Image Search to better understand your images.
Snapchat is a popular messaging and picture exchanging application that was created in 2011 by three students at Stanford University named Evan Spiegel, Bobby Murphy, and Reggie Brown. The application was first developed to allow users to message back and forth and to also send photographs that are only available from 1–10 seconds until they are no longer available. The app was an instant hit with social media members and today there are up to 158 million people using snapchat every single day. It is also estimated that Snapchat users are opening the application approximately 18 times per day, which means users are on the app for about 25–30 minutes per day.