It seems that it's becoming an increasing trend for artists to preview their upcoming album releases online. It could be a video of a rehearsal or a clip of each song that is going to be on the album.
I think if you see an artist live right before their next album releases you can expect to hear some of these songs live. However, with social media, it's easier than ever for artists to give fans a tease from their latest project. Many artists have released clips of each songs before you can buy the CD in stores or from them.
So my question is, do these previews really affect whether or not you're going to buy the album?