"The continuous shuffling machine is a device that randomly inserts discards back in the deck. With one in use it is like playing against a freshly shuffled shoe every hand. This machine is not to be confused with an automatic shuffler that shuffle and entire deck or shoe."

http://wizardofodds.com/blackjack/appendix10.html

"The other weapon is an automatic dealing shuffler. No it's not the type of automatic shuffler that you've been use to seeing, you know the one that is automatically shuffling 6 decks of cards while a second six deck of cards is being used by the dealer. Nope this automatic shuffler is quite different. It is known as a continuous shuffling machine (CSM) and it was created to eliminate card counting and shuffle tracking. It looks almost like a black box and it works like this.

After every round or so (casino discretion) the dealer will scoop up the discards and return then to the hopper of the CSM where they are mixed randomly with all the other cards. Depending upon the number of players, you would have at most only a half of deck of cards "outside" of the CSM. This means the penetration is at best 10% whereas in the traditional game it's more like 50 to 75% (penetration refers to the percentage of cards that are used up till the shuffle). The CSM appears to have all but eliminated the advantage play based on card counting and shuffle tracking.

The manufacturers of CSM's are also making the pitch to casinos that they will be able to deal more hands per hour. They are correct on this point because there is never a pause for shuffling using the CSM (think of it as one long continuous shoe being dealt)."

http://www.casino.com/blackjack/article.asp?id=317