What we are seeing is perhaps the second generation of women who were raised with effective Birth Control options and the power of the internet.
As I've mentioned before, men have been able to have affairs throughout history with little or no consequence. On the other hand, it was the women who bore all the risk. Now with effective Birth Control, an increasing amount of women are doing what men have doing all along.
But I will rush to say that while there is an increasing amount of Black - White interaction, I think it's raising proportionately with activities with non-Black men as well. Remember, this forum caters to interracial relationships. But you can find countless sites that cater to White - White encounters as well. So don't think that by just exploring what this forum has to offer, it isn't the only one out there that caters to open relationships.
Finally, the power of the internet can't be discounted. White males who find this interesting are discovering that they aren't alone. There is a whole bunch of white guys who love the concept of their wives getting Spaded. They mention this to their wives and the seed is planted.
Another scenario is the wife just bouncing around the net. She sees what's happening and becomes interested. If she is interested enough, things will start to happen - either the start of an open relationship or an affair. Again, with various Birth Control options, this is less of a risk than it was during her mom's generation.
That's my take on this topic. Love to hear what others think