Due to its popularity, some have begun to use it as an SEO tool to make their website more visible. That’s an altogether fair and useful idea for small business owners – a valid and simple attempt at link building. However, the more often a web page is submitted and tagged, the better chance it has of being found, so spammers have started bookmarking the same web page multiple times or tagging each page of their web site using a lot of popular tags (regardless of relevance), forcing programmers to constantly adjust their security system to overcome abuses (thank you Wikipedia for that content that I just paraphrased). Furthermore, since social bookmarking generates backlinks, social bookmark link generating services are used by some webmasters in an attempt to artificially improve their websites’ rankings in search engine results pages. This is all black-hat SEO 101. If your agency tries to use this to artificially inflate your rankings, move on and find a new agency!
Examples of social bookmarkings sites include: Twitter, Pinterest, Reddit, StumbleUpon, BuzzFeed, Delicious, and Digg. There are hundreds, but those are the ones that are most notable – all of which receive millions of unique visitors each month. Yes, Twitter and Pinterest are considered bookmarking sites because it is a place to gather links and categorize sites (hashtags, shared shortened links, etc.), besides its other uses.
Using social bookmarking wisely can be a great way to share your content, get it categorized alongside similar, relevant content, and to try to grow your content’s reach. However, it is also subject to abuse, so use it wisely.