When it comes to shopping, there’s no question that flash sale websites have changed the game. In fact, names like Gilt or HauteLook have become as much a part of our style vocabulary as, say, Barneys or Topshop. The trend — which originated in France — allows shoppers to scoop up high-end clothes, shoes, accessories, travel deals and lifestyle goods for a major discount, typically up to 70 percent off retail.

advertisement | advertise on newsday

The catch? Most only offer them for a day or two and supplies are limited, adding a gamelike — and often addictive — aspect.

In most cases, the sites — which deliver daily e-mails to your inbox alerting you to sales — are free but members have to be invited by other members.
In the spirit of getting the best stuff, we asked staffers at four popular sites to give us tips on how to best navigate their online sales.

Gilt (gilt.com)

Probably the most recognized among its counterparts, Gilt offers 36-hour flash sales on everything from coveted designer gear to bottles of wine.
Invite-only? Yes. “But members are strongly encouraged to invite friends,” said founder Alexandra Wilkis Wilson And, when the pals you’ve invited sign up, you’ll score a nice little treat — a $25 credit on your next purchase.
Alexandra’s tips:
Log on early
New Gilt sales begin daily at 12 p.m. and new merch sells quickly, so log on a minute or two before the sale kicks off. "It’s like stretching before running a race," Wilkis Wilson said.
Set up notifications
Once you’ve joined, go into your preferences and set up notifications about specific sales you’re interested in.
Fill your cart
Even if you're not 100 percent sure if you want an item, grab it anyway. You’ve got 10 minutes to think about it, before another member can snatch it
Search by size
“The worst thing is to fall in love with something and see it's not available in your size,” said Wilkis Wilson.
Use the wait list
Yes, it’s a dreadful feeling to see that pair of Burberry boots already sold out, but using the site’s waiting list could pay off. Gilt occasionally scores more of a popular item.
Our recent Gilt purchases: Sophomore  T-shirt ($29, originally $69), Alexander Wang lattice sweater ($209, originally $550), H2Pro flat iron ($99, originally $180).
Rue La La (Ruelala.com)
This 2 ½ year old site is a lifestyle site on which users can buy clothing, fine food, spa packages and getaways at up to 70 percent off. Members get a daily e-mail at 11 a.m. alerting them to the day’s boutiques. “That’s when the curtain goes up,” said Stacey Santo, the site’s VP of Marketing.  
Invite-only? Yes.
Stacey’s tips:
Sign up for reminders
If you know a brand you love is coming up, you can set a 9 a.m. reminder so you don’t miss out, said Santo.
Use the 'quick buy' function
If you spot something you absolutely want (like something from last week's Chanel sale, perhaps), use the quick buy format, which allows you to score the item in two clicks and immediately return to browse for more with no added shopping costs.
Take a chance
Unlike other similar sites, ruelala.com has a liberal return policy, allowing members to get cash back or store credit on certain items.
IDEELI (ideeli.com)
The first invite-only site, Ideeli has been operating since 2007 and offers 10 to 12 new daily sales at up to 80 percent off designer apparel, home goods, kids’ clothes, travel and beauty.
“We bring our members brands they know and love but also under-the-radar [labels], so there’s a real element of discovery,” said Ideeli’s executive director of brand marketing Tamara Rosenthal.
Invite only? Yes. The site is free once you’re invited, unless you become a “first row” member, which gives you early access to sales for $7.95 per month.
What we love: Ideeli offers themed sales that take cues from what’s hot at the moment. Past theme sales have included the safari trend and “Sex and the City 2” fashion.
Tamara’s tips:
Look ahead
“Always check the coming soon tabs,” said Rosenthal, who recommends clicking on brands you like to get a reminder e-mail.
Shop early
Each new sale starts at noon, so it’s best to be at your computer a few minutes before. “Or, become a First Row member to get the best access,” Rosenthal said.
Follow them
Through FB and Twitter, the site highlights the day’s best bets, on-trend items and deals you can’t pass up.
Shop it to me (shopittome.com)
Veering away from the sample sale format is shopittome.com, a site that essentially acts as a free personal shopper.
How it works: Initially, members log onto the site and select from a list of more than 700 brands they’re interested in (everything from Miu Miu to J.Crew), as well as apparel type and sizes. From there, the site will scour the Internet and notify you when the items you're interested in go on sale.
Invite-only? No. Anyone can sign up, free of charge.
A perk: Users can choose how many times a week they want to receive e-mail. The site’s founder and CEO, Charlie Graham, suggests signing up twice a week if you’d rather not get bombarded. Of course, by doing that, you run the risk of missing out on certain sales.
Charlie’s tips:
Take time
Make sure to spend time going through the brand list. With so many options, it’s easy to miss labels you love.
Don’t commit to one size
Since there’s no limit to how many size options you can initially check off, users should put in a range. 
Use the site to learn
Love a particular brand? Shopittome.com can suggest similar labels and designers you might not know about. "It keeps the experience very personal," Graham said.
Hey, readers, want to become a member of Gilt, RueLaLa and Ideeli? Use these invites codes created just for you!
Ideeli invite code: amny2010
Rue La La invite link: www.ruelala.com/amnewyork
Gilt invite link: www.gilt.com/amny