That charge jumps $26 for each additional hour and surges to a $170 starting price if there's more than one product involved. Want a piece of a store's swollen opening day take? That charge jumps to $340 for a full day and $15 for supplies. It's not much cheaper on the West Coast, where Warehouse Demo Services has been helping such companies as Kraft ( KFT), General Mills ( GIS) and Procter & Gamble ( PG) hand out their wares at Costco location in California, the Pacific Northwest, Hawaii and Alaska since 1989. The cost of doing business there is also $150 per day and $170 for two vendors. Not to be left out of the fun, Wal-Mart ( WMT) and Sam's Club dumped their 10,000 in-house sampler jobs and gave them to independent firm Shopper Events. So what does it cost Unilever ( UL), Keebler and Nestle to put some Hellman's mayonnaise, Chips Deluxe cookies or DiGiorno's pizza into shoppers' mouths? It's $200 to $240 per store at Wal-Mart, but Sam's Club is open to negotiation. Oh, and companies still have to give out samples in carts with a giant Wal-Mart or Sam's Club sign above them. If that seems a bit steep, keep in mind that getting a customer to even try a product is the biggest part of the battle -- with companies spending more than $94 billion in advertising alone last year just to get people to consider a product they may never have sampled, according to Kantar Media. With the free sample, a company gets the customer to try a product without putting up a price barrier, while the customer gets a "free" item while not having to gamble a portion of that week's grocery bill on a product they may not even like. With all of that on the line, Livingston says dedicating sample-specific personnel and resources toward putting a supermarket's best foot forward is an investment everyone ends up enjoying. "Retailers who do this for a while have samplers employed and put a little extra effort into giving out their samples," he says. "You can tell if a smaller retailer hasn't done much sampling if there's just a teenager behind a card table with toothpicks." -- Written by Jason Notte in Boston. >To contact the writer of this article, click here: Jason Notte. >To follow the writer on Twitter, go to http://twitter.com/notteham. >To submit a news tip, send an email to: email@example.com.