Don't rely on any site to provide you with the buttons you need or want in order to share the content. Do a Google search for the "AddThis Toolbar" and then install it on your computer. AddThis browser extensions are available for Internet Explorer, Chrome, Firefox, and Safari. The toolbar will allow you to choose from over a 100 different social networks and bookmarking sites and give you the buttons for those sites right in a toolbar on your browser. Choose your sites, make sure you sign into them individually, and when you browse the internet and find content you want to share, just click on the buttons of the sites you want to share them on. It's real easy and so much better than the choices you are given on most sites since these are the sites you will be working with most often.