To borrow:
Social Media and Everyday Politics is available to borrow from more than 400 libraries in 30 countries around the world; many are listed in Worldcat, and if your library does not have the print or ebook versions, you can always ask your library to order it (including directly from the publisher; see below)!
To buy:
If possible, please order the book through your local bookstore or direct from the publisher. It is available as paperback, hardback, and ebook, at reasonable prices (especially for the paperback). You can request an examination/institutional copy from Polity / Wiley.