A SUSSEX couple are among the most successful authors of last year – shifting more than 650,000 copies between them in 12 months.

Vloggers Zoe Sugg and Alfie Deyes have four books between them in the top 60 best-selling books of 2015.

Millionaire YouTube star Zoella leads the couple with her Girl Online: On Tour named the 20th highest selling book of last year. Her debut novel released in 2014 still sold strongly throughout 2015 to finish at 34th in the annual bestseller charts.

Her partner Alfie Deyes saw his The Pointless Book 2 come in at 39 in the charts, 19 places ahead of the first volume of the series.

The pair, who have enjoyed a meteoric rise to fame and have millions of online subscribers to their YouTube channels, recently asked fans to respect their privacy and not visit their £1 million Brighton home.

The couple went on a New Year’s internet detox – switching off their social media for a trip to Cornwall – but blogging about it afterwards.

Zoella said: “It’s so easy to get lost in the world of social media and before you know it, you know what everyone has had for breakfast, lunch and dinner, then followed everyone’s day via twitter and snapchat and not actually lived your own day.

“I honestly shock myself with how much time I spend refreshing everything on my phone so it’s nice to leave it alone for a while."