Hello, here in the forum are lot of ping lists. When the list have 500+, there are lot of visits possible? How much?
Search for the best pinglist . Too much ping to a single RSS directory site can be harmful for your blog as they will ban your blog. Use some kind of ping optimizer with that kind of big ping list.
When you say visits do you mean human visits? This is secondary to what pinging technically is for. Pinging tells the SEs that there is new content that should be crawled.
Be aware that duplicate pings to the same RSS directory can get you banned as said by "automagic". Use with care.