08/07/2013 12:45 EDT

Celebrities Who Make Fashion Items Sell Out: Kate Middleton, Lindsay Lohan And More Crash Websites (PHOTOS)

LOS ANGELES, CA - FEBRUARY 9: Actress Lindsay Lohan steps from the car as she arrives to court for an arraignment hearing in connection with the alleged theft of a $2,500 necklace on February 9, 2011 in Los Angeles, California. Lohan has been charged with a felony count of grand theft for allegedly walking out of a Venice, California store with the necklace in January. (Photo by David McNew/Getty Images)

When Kate Middleton wore a simple polka dot dress to introduce her son Prince George to the world, it was only a matter of time before women were scrambling like single girls after a bride’s bouquet to own the Jenny Packham sheath.

To our dismay, the dress was made exclusively for the Duchess of Cambridge, but that didn't stop Packham's online retail store to crash anyway.

“The Kate Effect” which has seen anything Duchess Kate wears in public turning to fashion gold happens rather frequently. Catherine Cambridge's floral maternity dress by Séraphine, which she wore as she, Prince William and their newborn were leaving Kensington Palace for the Middleton compound, now has a month long waitlist and we bet that the next time Kate is seen in public, her outfit will be sold out within hours.

When a star is seen wearing a designer's outfits or accessories, sales usually skyrocket. Since most of us won't be starring in blockbuster movies, we get a kick from buying celebrities' clothes to add a little bit of glamour to our lives.

Here are some celebs who have caused fashion items to sell out:

Lindsay Lohan

Remember when Lindsay Lohan wore a tight white Kimberly Ovitz mini dress to court? While a hearing may not be the best place to spot hot fashion, it is for someone who spends more time in court then on a movie set. The $575 dress caused a major fashion frenzy and sold out shortly after Lilo was spotted wearing it with her signature big sunglasses.

Emma Watson

On the opposite end of the troubled star spectrum is one of Hollywood’s new hot commodities, actress Emma Watson. The "Harry Potter" star wore a Scotty dog print scarf from Crumpet in 2012 which sold out after the Brit was seen strolling around wearing it paired with a floor length black wool coat.

Alexa Chung

It’s not every day a corporate e-commerce site implodes because there’s just too much demand.

Brit actress Alexa Chung was to blame for the overtime incurred by the IT department of Madewell for having to fix the website crash after shoppers flocked to the site to buy Chung's hipster-inspired line.

The preppy brand partnered with Chung in 2011 to create the fashion line which caused line-ups outside of Madewell stores and soon after, insanely inflated Ebay sales for the same items.

Marc Jacobs

From time to time, a man wears a lace dress and then it sells out. That’s exactly what happened when Louis Vuitton designer Marc Jacobs wore a black lace tunic to the 2012 Met Ball.

The Commes des Garcons tunic reportedly sold out at Barney’s New York after Jacobs wore the frock with white boxers and black pilgrim shoes. We’ve yet to confirm if the dress was purchased by women or men.

Michelle Obama

From The Met Ball to The Inauguration Ball, First Lady Michelle Obama has been known to have quite the effect herself. The low maintenance but stylish mom wore an inexpensive ASOS checker print dress with a full skirt in February and it sold out shortly after on the online retailer’s site.

This isn’t the first time Obama has caused a fashion frenzy of this magnitude. FLOTUS wore a $35 Jason Wu for Target floral dress which also sold out quickly in stores and online after she was seen wearing it at low-key dinner in Florida last year.

Pippa Middleton

With that, we come full circle and back to the Middleton clan. Kate’s sister Pippa has caused her fair share of shopping pandemonion. The royal in-law was snapped at a party in London in May wearing a pretty peach Tabitha Webb shift dress which sold out only a few days after photos ran online.

This is a lesson for all budding designers: Get your clothes on the back of a celebrity or royal and you're well on your way to making a bundle thanks to eager shoppers.

The dress that shoppers want but can't have:

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