Has anyone redeemed Mypoints for the $50 (3,750 points) and $75 (5,750) United travel certs? Reason I am asking is as I am wondering:

a) Is there a minium ticket value before these discounts can be applied?
b) Are these electronic and hence instant, or are they paper and mailed which would take about a few weeks?

There is no description of these certs on the Mypoints site....

Thanks!