MySpace was massively larger than LiveJournal. In 2006, MySpace literally became the most visited website in the US, as per https://en.wikipedia.org/wiki/Myspace (and I also recall it being mentioned quite a bit at the time).
For another comparison: NewsCorp acquired MySpace in 2005 for $580 million. Six Apart acquired LiveJournal in 2005 for just a few million, and sold it to SUP in 2007 for somewhere around $25 million if I recall correctly.
Disclosure: former Six Apart employee, although several years after the sale of LJ to SUP.
