MySpace has always been famous in its origin country and it has never being particularly well received outside the UK. On the other hand Twitter has always been flourishing not only in the UK but also worldwide and is specially popular in countries like the UK. Even so with the raw traffic, Twitter managed to overtook MySpace in the UK.
According to Hitwise UK, Twitter is observed as the most visited websites in the UK and by this for the first time Twitter emerged out to be the largest website in the UK. Just last week Twitter was counted as the 27th most visited website and MySpace to be the 28th. While looking at social networks alone, Facebook was the biggest UK site, followed by YouTube and Bebo, with Twitter in the 4th place and MySpace in the 5th.
But who knew that this 27th ranked website will do so good and will emerge among the most popular and most hit website. Robin Goad, research director for Hitwise UK, says :
If anything, Twitter is even more popular than our numbers imply, as we are only measuring traffic to the main Twitter website. If the people accessing their Twitter accounts via mobile phones and third party applications (such as Twitterrific, Twitterfeed and Tweetdeck) were included, the numbers would be even higher. Of course, MySpace also picks up a significant amount of traffic outside of the MySpace.com domain, particularly via mobile platforms.

These figures should be read in the context of a market (the UK) where MySpace has never been as dominant as in the US, and in which Twitter has been usually successful.