And you must achieve this number of submissions to make an impact, otherwise all the work invested in your links page is simply in vain. For example, if you have a 3,368,420 hits page , you need at least 1000 submissions to get 20 signups from your page. The RateSaver links page is living proof of this. It is now getting thousands of hits per day . Please keep in mind that it takes a while for submission services to incorporate your links page, so don't expect that high sort of level in the first months after notification.
Most webmasters try hard to get more traffic to their sites.
It is their number 1 concern. So, they try to have their site included in as many search engines and links pages as possible. This way, lots of people will find their site. So they use url submission services instead. These url submission services maintain large databases of search engines and links pages.