A lot is to do with traffic and promotion, we had a dry spot in February-March, as we had reduced our advertising activity.
Our servers are "fully loaded" with features so I don't think it's necessarily a feature thing.
High Performance, Low Contention, Hosting
Elastic Sites (HIgh Powered Hosting Accounts) with 1 to 20 CPU Cores, 4 to 42GB of RAM. (Power of a VPS without the hassle)
Shared, Reseller, VPS, Dedicated & More available