Adam did not become a regular in the Rangers team until the 2006/07 season but he was an immediate success, scoring 18 times from 74 competitive matches over two seasons. This success earned him a new five-year deal with Rangers in June 2007 but he failed to add to his goal tally in nine Scottish Premier League matches at the start of the 2008/09 season. Stuck on the left-wing and overweight Adam was subsequently loaned out to English Championship club Blackpool, for whom he was sent off during his debut! This lapse in discipline did not deter the Seasiders from signing him permanently the following summer. Adam quickly became a firm fans’ favourite at Blackpool who were promoted to the Premier League at the end of the 2009/10 season. He scored a crucial penalty against Nottingham Forest in the first leg of the play-off semi-final before curling a wonderful free-kick into the Cardiff City goal in the final at Wembley, Blackpool prevailing 3-2 in an entertaining match.

At the turn of the year, Blackpool looked to be in a comfortable position in the Premier League. Liverpool tried to buy 25-year-old Adam from Blackpool in the January 2011 transfer-window. Ian Holloway’s opinion at the time was that the offer was “disgraceful” for the key to Blackpool's survival. The club slid down the table with relegation confirmed on the final day of the season, despite Adam's efforts that got him nominated for Professional Footballers' Association's Player of the Year. Blackpool activated an option to extend his contract by another year, but six weeks later he had signed for Liverpool, despite Tottenham's last-ditch effort to steal him. Adam had gained a reputation as a dead-ball specialist from corners, free-kicks and penalties, even scoring direct from a corner in February 2011. Alex Ferguson's quote: "Adam's corners are worth £10 million alone," didn't ring true as he struggled to impress Liverpool fans, although he did provide a few assists. He missed a penalty at Wigan in December and put another spot-kick into orbit during the shoot-out that followed the drawn League Cup final in February. Adam played in nearly 70% of Liverpool's first-team matches in 2011/12 but his debut campaign was ended by lateral knee ligament damage suffered against QPR on 21 March 2012. Maybe Adam was not suited to life at Liverpool where he was just a small fish in a big pond compared to life at Blackpool where he had been the big fish. Adam left Liverpool for Stoke City on the last day of the 2012 summer transfer window.

Adam played in twenty-seven of Stoke's thirty-eight Premier League matches in 2012/13, scoring three times. Adam upped his total of Premier League matches to 31 in the 2013/14 season, in which he scored 7 times. He also appeared in four domestic cup-ties, scoring once. Adam made a total of 35 appearances for Stoke City in 2014/15 and scored seven goals. On the last day of the season, he scored in Stoke's 6-1 hammering of the Reds and signed a one-year contract extension in the summer. He was on the fringes of the first team in 2015-2016, making just twelve league starts but proposed loan moves during the January transfer window failed to materialise. He stayed at Stoke in 2016/17, making 17 starts and suffering the indignity of being a substituted substitute when they faced Liverpool on 8 April. After relegation in 2017/18, Adam remained at Stoke, where he had been critical about the performances of many of his teammates. He made just four Championship starts in 2018/19 and it was no surprise when he was released at the end of the season. On 22 July 2019, Adam agreed a one-year deal with Championship side Reading. Only eight of his 21 Championship appearances there were starts and in September 2020 he agreed a two year deal with his boyhood club Dundee.