Those of us who cut our teeth on playing casino games at a land based casino will remember that on this side of the Atlantic there were very few slot machines available. In fact the only place you were likely to have much choice of slot machines was in the specialist arcades and not in the casinos. Nowadays of course most of the online casinos lead with their casino slots on their home pages, having recognised that the slots are now the favourite casino games played online, particularly among their new customers. The casino slots that we can now enjoy at the online casinos are clearly a far cry from the original 3-reel slot machines we used to play, with as many as five reels combining to offer multiple winning combinations on every spin. A recent addition to the casino slot genre at the All Irish casino does not even use reels, with the winning lines determined by falling blocks instead. This proliferation of casino slots hosted by the online casinos is the defining factor of the online casino business, because the slots almost certainly define which online casino most new gamblers will choose to register and to play their casino games with. The online casino software designers have not even stopped at reproducing sophisticated variations of the original slot machines, because we can now play a growing range of video slots online with themes varying from popular television programmes to horse racing for sports gambling fans. The variety of casino slots is clearly not the only factor contributing to their popularity, because they also tend to be the casino games which can be played for the lowest stakes, and are therefore also within the range of most budgets. Most online casinos also offer rolling jackpots and a variety of bonuses associated with their casino slots so that even those online casino games players with limited budgets have the opportunity to win substantial pots.