Bids don't accumulate. It just takes the maximum bid that you sent.
Interesting design choice, that makes it an entirely different game play. I expect people to be less likely to overbid by a tiny amount this way, but it levels the playing field for everyone: nobody can build on their previous bids.
Maybe, when your site has many active players, you can experiment by adding "accumulation games" to see which one is more appealing.
Accumulation means adding up with the previous amount?
In that case in a regular auction how do we play it? You call 2 then I call 3, then you call 4. Basically you are adding more 2 with the previous call. So it's accumulation. I was expecting the same but it seems it's not the case.