[adam]

Congrats on shipping. :) As others have mentioned, I was turned off by the pricing model. Your idea of taking a % of amount saved, or charging me after you've achieved savings would be much more palatable.

That said, if you have the data for it, it would be awesome to show some proof that this is a widespread thing - that prices do fluctuate regularly and there are these drops in price people can take advantage of - if they are using your service. I think that would help your case.