I wouldn't recommend any auto submission service. There's only a handful that really matter and manually submitting is easy enough. Some people recommend NOT submitting, but instead let the search engine find you naturally.
Auto submission is great for the smaller search engines, for the larger ones naturally letting them find you seems to work best.
Website promotion is not just a technique you have to work hard for you and your clients. most mass submitting softwares are uselss or less effective or some time they become useless. the numbers are not much important the quality is important.
I am with internetbrother. Auto submission gives fast result but not for so long time. There will be some sideeffects too of that.
all webmaster recommend you to avoid it. Sumit the url indiviualy in each search engine its hardly take few hours . atleast you will be confident that you have done it by your self.
I suppose it wouldn't hurt to use a free auto-submitter but I would never pay for a service like that. My two cents.