mailing lists where members can mail each other. Like with mailers they
are usually credit based. What this means is that you receive messages
through the system which you then click on a link inside the message
and earn credits for viewing the site.
Most safelists also provide for text and banner advertising for which
you can also earn credits to place your own ads on their site for other
members to see.
Usually there is a limit on the number of times and the amount of
message you my send for example 500 per week or every 3rd day if you
are an upgraded member.
Safelists should not be confused with Viral List Builders although they
all serve the same purpose and that is to help you build your list
safelists, viral list builders and mailers each have their own
procedure, execution and function.
In general all of these sites where you can mail to other members are
great list builders and cash flow generators.