it means when a wholesaler has a property under contract and advertises to sell it ,whether on craiglist or thru email and says something like 

"totally assignable contract  add your price or commission  to your buyer"

which leads to a multiple amount of sellers advertising the same property as the original seller thus a 

'daisy chain"     happens a lot on not only properties but notes also

@Account Closed, I thought it just meant when a Wholesaler "sells" it to another Wholesaler (for a higher price), who then "sells" it to another Wholesaler (for an even higher price), and so on, rather than many Wholesalers trying to advertise it for more or less the same price.

There are many threads here on BP started by (newbie) Wholesalers asking if it's OK to buy contract/s from other Wholesalers who they know, because they THINK they have a Buyer lined up (rather than bothering with finding their own deals). I believe it's the ESCALATING "daisy chain" pricing (read: no longer a bargain) that helps give wholesalers the bad reputation they generally have/deserve. [But if your definition is more correct, I will defer to a BP correction]. Cheers...