Don’t miss this very good interview–does he ever give a bad one?–that IAC’s Barry Diller did with The Wall Street Journal’s Shira Ovide in today’s edition.

After a bruising court battle with shareholder and cable mogul John Malone of Liberty Media (LINTA), Diller finally broke apart the Internet conglomerate six weeks ago. His reason: IAC (IACI) had become too complex and its stock had suffered due to the operating confusion.

Here are BoomTown’s three favorite Diller killer quotes from The Journal interview …

On the breakup:

“I don’t have answers for anybody else. What I know is that internal complexity makes for superficiality. There’s never essentially a pure story unless there’s a pure product line that has its own shining clarity.”

On Internet advertising:

“You really want to get a headache? Try to understand Internet advertising. Social-networking advertising is being discounted because there is so much inventory [of available ad spots], and because methods have not yet been found to make it very effective. Will that get figured out? I absolutely believe it will. What form will it take? Absolutely unknown.”

On his fight with Malone:

“It is water down the drain. It’s unfortunate that executives of Liberty forced us into this process that resulted in the court affirming our position, but they did. It was hurtful to the company in which they’re investors, it was hurtful to me, it was a waste of time and money. It’s over. It certainly has no effect because my relations with John Malone are right and proper. They can have board members, but I outvote them.”

And, if you want more Diller unplugged, about all of the above and more, here is the highlight reel from my interview with him in May at the sixth D: All Things Digital conference.

Don’t miss his take on Hollywood children’s teeth.

The entire interview will go up next week in this blog, but here is the shorter video for now: