Slow website on shared hosting. Migrate to Linode?

I have been running a website on cakephp for a year now and it was working fine till last month. Due to some marketing and viral activities my traffic has increased to daily hits of 1300. Since then I am experiencing slow performance. I have tried optimizing website using various tools and tutorials, but no change. I am now thinking that shared hosting is the reason here. One of my friend has suggested my to try out Linode, since it is scalable and has dedicated servers. I wanted to ask my fellow developers what are their experience with Linode. What would you guys suggest?