Dunno normally I just slap down hints for traps or ambushes, it's worked freakishly well at times lol had a fight with Maneater the other night not goin so well an suddenly it was, Did not know about the whole health restore lol explains what has been goin on.
I've been saved by it before, used it once when I actually needed to get back to my souls with a sliver of health and very little grass in Latria.
I generally don't recommend them if I come across one with around six recommendations, as hopefully the six heals helped the character out, and deleted mine after I got healed. It's a useful tool.
On the other hand, I do get a little frustrated when I see them with like 600 recommends. The person obviously left the message last week and doesn't need anymore health. I'm less inclined to recommend a message with a lot of recommendations.
It's just people looking for recommendations. The free heal is nearly useless unless you're in the middle of a boss fight and don't have time to heal which usually means you just need to try a new strategy. Healing items are abundant anyway.