If you are at a brunch party, which foods do you pick? The ones you like?

Partly yes, but much rather those that are easy to access: those with the wrapping off, item unpacked or sliced up nicely in a row. If you need to spend even a bit of effort accessing it, you'd rather pick something already prepared for you: even a minimal threshold will keep you away (except for that 1% of guests who are too hungry or too enthusiastic about a finger food to leave it behind).

A website registration to access a free demo, a hard-to-open door in the entry of a shop, the need to ask an otherwise busy sales clerk for help or fill out a complicated tax form are barriers that marketers and policy makers are not even aware...but these keep dozens of hungry customers or otherwise law-abiding citizens away from engaging.

What is your barrier to entry...?