On October 13, 2009, the Mega Millions consortium and Multi-State Lottery Association (MUSL) reached an agreement in principle to cross-sell Mega Millions and Powerball in American lottery jurisdictions, with the two groups referred to as the "Mega Power Lottery" by many users. The expansion occurred on January 31, 2010, as 23 Powerball members began selling Mega Millions tickets for their first drawing on February 2, 2010; likewise, 10 Mega Millions members began selling Powerball tickets for their first drawing the next day. Montana (joining Mega Millions on March 1, 2010) was the first jurisdiction to add either game after the cross-sell expansion. Nebraska (March 20, 2010), Oregon (March 28, 2010), Arizona (April 18, 2010), Maine (May 9, 2010), Colorado and South Dakota (the latter two on May 16, 2010) also have joined Mega Millions since the expansion.
73-year-old H from El Salvador had one question on his mind when the Powerball jackpot hit $1.5 billion: Where can I buy a Powerball ticket? Luckily the answer was theLotter and he won the $1 million 2nd prize in the historic draw on 13 January 2016! "I won!" he shouted out when he heard the news. He plans to travel and retire in style. Read his story here.
Mega Millions' second-largest jackpot, $648 million, was for the December 17, 2013 drawing. Two winning tickets, one each from California and Georgia, were sold. The holder of the Georgia ticket claimed the next morning; they selected the cash option, which amounted to $173,819,742.50 before withholdings. The holder of the California ticket claimed on January 3, 2014. (The California ticket holder received an equal share, but potentially a larger cash-option amount, as California lottery winnings are exempt from state income tax)." 
In 1998, Florida was given permission by its government to participate in a multi-state game. It was set to offer Powerball; but in early 1999, new governor Jeb Bush prevented Florida from joining since he believed Powerball would hurt the existing Florida Lottery games. In 2008, Governor Charlie Crist finally allowed Florida to join MUSL, on Jan 4, 2009.
This method specifically has faced criticism recently from a number of lottery organizers such as Camelot, the UK National Lottery organizers who are not happy with companies “selling tickets” (selling bets on outcomes of their established lottery draws) for prices sometimes even cheaper than Camelot themselves sells their tickets. This legal and corporate dispute looks set to continue for the foreseeable future, in the mean time you can continue to buy Powerball tickets online, only now you are aware of the key differences between the two business models.