I'm not not parent, but - I've purchased a few time-blocks for a different campaigns over last few years and it brought in significant traffic, a bit more conversions, but despite being able to target a subreddit, it is still hard to get your money's worth if you are promoting a brick and mortar store. Unless that store offers tangible goods sold online as well. Location constrained and in-person transaction type of services saw less of a bump in revenue. That is probably true for online advertising overall. My 2 cents