Will a spider follow this type of link? If so, is there a way to prevent that from happening? We're afraid that noindex nofollow on the resultant page is found too late in the process - the spider already hit the page to find that tag.
(We are being charged for click throughs on the link, so we'd prefer spiders don't cause charges by following it. However, we DO want the page that the above script resides on to be indexed!)
On the other hand, are the number of hits likely to be incurred by indexing spiders so few that this concern is of little relevance?