I mistrust anyone who cold calls, though I understand why its
sometimes a necessity. My past experience has been that if the
salesman is cold calling me instead of me calling them, I don't need
it.
Most Lawyers belong to at least one association of lawyers, whether
its the local County Bar Association, or a Statewide trade
association focused on a specific industry within law. Whenever I
go to a meeting there is a section dedicated to sponsors who have
booths either in the hallway or in the back of the room. If you can
reduce your product to something that can catch my attention during
the breaks, I often stop to see what it does, what it costs, etc.
Also most lawyers received a trade magazine from one or more
Associations, and those magazines are filled with advertisements
ranging from full page display ads to little classifieds in the
back. I tend to at least scan the ads, and apparently so do many
other attorneys. There are also service provider directories which
if you have a unusual niche can be useful.
I also get tons of un-solictated junkmail and postcards. Unless I
have an obvious immediate need for whatever is being solicited I
tend to junk it all the same day.
Personally, I think being a booth sponsor at a meeting is the best
way to get credibility, though I don't know how it translates into
sales for any of them.