The assumption you're making is incorrect. There is not an infinite number of low-fee transactions.

Yes, the average fee will go down compared to today with Block75, but this will balance itself between demand and the minimum fee miners are willing to accept (not zero).

For example, add 200kb to today's max block size. How does that affect fees?
(200kb would likely be the first increase if Block75 activated today)

-t.k.

On Sun, Dec 11, 2016 at 4:55 PM, James Hilliard <james.hilliard1@gmail.com> wrote:
I think the main thing you're missing is that there will always be
transactions available to mine simply because demand for blockspace is
effectively unbounded as fees approach 0. Nodes generally have a
static mempool size and dynamic minrelaytxfee nowadays so as
transactions get mined lower fee transactions get accepted into the
mempool. An individual opting to not send a transaction would not make
the blocks smaller simply because there will always be other
transactions available(it would really only have an effect on the
transaction fees needed to get mined).

On Sun, Dec 11, 2016 at 3:40 PM, t. khan <teekhan42@gmail.com> wrote:
>
> On Sun, Dec 11, 2016 at 3:31 PM, James Hilliard <james.hilliard1@gmail.com>
> wrote:
>>
>> What's most likely to happen is miners will max out the blocks they
>> mine simply to try and get as many transaction fees as possible like
>> they are doing right now(there will be a backlog of transactions at
>> any block size). Having the block size double every year would likely
>> cause major problems and this proposal allows over a 7x increase it
>> seems.
>
>
> Block75 is not exponential scaling. It's true the max theoretical increase
> in the first year would be 7x, but the next year would be a max of 2x, and
> the next could only increase by 50% and so on.
>
> However, to reach the max in the first year: 1) ALL blocks would have to be
> 100% full and 2) transactions would have to increase at the same rate. We'd
> have to be doing 2.1 million transactions a day within a year to make that
> happen, and would therefore need blocks to be that big.
>
> Realistically, max block size will grow (and shrink) at a much slower rate
> ... even more so with SegWit.
>
>>
>>  The main problem with this proposal I think is that users effectively
>>
>> have no way to stop the miners from increasing block size
>> continuously.
>
>
> Yes they could, simply by not sending transactions. Users don't care at all
> about block size. They just want their transactions to be fast and
> relatively cheap.
>
> -t.k.