[danudey]

Since sales taxes are added at the time of purchase in North America, none of that ends up mattering because the randomness of someone's shopping cart plus the percentage of sales tax makes it impossible to price your inventory in such a way as to consistently benefit the retailer.

Worth mentioning that despite not having a one-cent denomination, products are still priced in cents - e.g. in Canada you still price something at $2.79 even though we have no pennies. It's only at the payment step, when cash is being used, that anything is rounded off.

I mean, retailers could certainly increase their shelf prices, but if they were going to do that they would do so anyway, and the $X.99 pricing pattern exists for a reason so there's not really anywhere to increase those prices by some small amount that wouldn't put people off anywa.