What happened between March and April?

Following a review of Isa in another thread, I've been looking at levels of visits by leading banks in Alexa. And obviously something happened between March and April this year. In those months, both IS and FT down quite visits (see graph) to levels of late 2009 ...

Meanwhile, up 123rf, and a little Shutterstock. Dreamsteam is maintained with slight upward trend.

Meanwhile, medium-sized banks are also rising, especially Can and Deposit ... I do not think that affects a lot. But on the whole must be taken into account.

The traffic is not sales (ahem) but clearly a trend. And the question is, why went some buyers of IS and FT between March and April?

and ...what a coincidence! IS and FT were the two banks lowered their royalties to its contributors ... Will there be justice?...

...I think not. In FT and IS, we have less sales and less royalties ...