Depends on what you want to use it for. I haven’t been sucked in thus far. I would really only use something like this to keep track of things that I want, so I tend to find the other aspects of the site to be unnecessary and a bit annoying.
I would recommend using Want Worthy instead if you’re looking for a site to keep track of things you like or want. It claims to be a “universal fashion wish list” but it really works for anything. You just download it to your browser’s toolbar, and click the link anytime you like or want something; it automatically saves the picture, link, price, and item information to a list. It’s very simple and has no social networking or other obnoxious/complicated aspects to it whatsoever.
I will occasionally browse Pinterest or use it to look for something, but you don’t need to be a member to do any of that.