New Links are links that we first seen on the internet in the reported day. From time to time you might see old links reported as new. That is because, sometime, web crawlers might find links on the web a bit later than the date the link was created.
Lost Links are links that previously had a Live status that has turned in a Broken status. Keep in mind that a link might be Live today, Lost tomorrow, Live again and so on. Everytime we find it Broken we compare to the previous state and if it was Live we report it as a Lost Link.
On a weekly basis we re-crawl all the links, so that each week, you get a fresh and complete view of the link data for this site.
After a few weeks/months the database for your campaign will become bigger and bigger and you will no longer see old links reported as new.