Kitson drops Lauren Conrad's 'lackluster' clothing line.

First Sarah Jessica Parker's Bitten clothing line bites the dust when its exclusive licensee -- Steve and Barry's -- goes belly up.

Also going buh-bye as a result: Venus Williams' Eleven, Amanda Bynes' Dear and Laird Hamilton's Wonderwall clothing lines.

Now "The Hills" star Lauren Conrad 's clothing will no longer be available at Celebrity Shopping Grand Central Station -- also known as Kitson -- in West Hollywood. 

Why, God, why, we wondered.

Seems sales were -- how to put this -- lackluster.

"Initially it was great," Kitson store owner Fraser Ross told OK!, adding that he tried in vain to get the reality TV starlet to make personal in-store appearances but no dice. 

"They need to realize it's no different than selling your album, your TV shows, your movies," Ross said.  "You have to keep promoting it."

What? You mean Lauren actually has to work?

Who has time for that when there are so many parties and premieres, like "The Dark Knight" world premiere in New York this week?

Isn't it enough that Lauren wears her clothing designs on the red carpets, like she did at at "Dark Knight," above, Monday night.

Man, being a reality TV star designer is so hard!

Photo: WireImage

BREAKING NEWS: I have just been informed, thanks to two intrepid and in-the-know readers' comments (see the comments below) that Lauren was NOT wearing an outfit from her own line at "The Dark Knight" premiere. Instead, she was wearing Dolce & Gabbana. Well, OMG, no WONDER her line flopped! Duh. Wear your own stuff, girl!