If you're not a merit source then you can probably run out of them very fast, especially if you're giving out more than one per post. Remember, for those that aren't merit sources you will only have them to give when people actually merit you (which isn't that frequent for most) and then you only have half the amount to 'spend' so it will quickly go and when users don't merit others more than one/two/three at a time often that leaves little merit to send on.
I agree, but my point was that by making it hard for merit sources to find meritable posts, you deprive those who would have received merits of the chance to award them. sMerit awards have half lives as you know, and this means that every sMerit awarded by a merit source adds virtually one more merit for the community to award. It's even worse than that, because if a merit source ends the day with some unawarded sMerits, then the replacement of those is delayed by a day. I've tried to make spammers aware that their activities reduce the number of sMerit available for their associates as well as themselves. However, they don't seem to get the message.