Do Indexing Services Leave Footprints?

I was thinking about this the other day. I use a very popular indexing service and I was thinking ... I bet so do hundreds of others maybe some not promoting the most ethical things.

Does anyone have any knowledge about this?

Could using an indexing service that is popular have a negative impact on your SEO?

Depends where the ping etc comes from i guess if its the same ip over and over then maybe it would raise some flags.

Indeed, if I am trying to ping multiple sites/articles I will use different pinging services just to be safe. I can guarantee most normal bloggers don't use any type of indexing services at all. Seems like an obvious footprint to me.

It depends on which service, if you are paranoid, you can create multiple social account, and share it manually, the indexing rate will not be as high as those service, but it can get the job done.