what kind of services are they offering you? There is a particular one that you think is the reason why the traffic on your website is increasing that much?
There are still other great PPC program other than Adwords.. known as: Questclick.com Linksnap.com ...
I took some time to check it out and I found itsclickzilla as a really useful site, offering services that I was looking for
If you just starting with ppc go with a yahoo because google is very competitive and has sophisticated algorithm.First inform yourself about it or you will lose money.Good luck
Have you considered to perform a make over on your site? maybe that plus a good PPC campaign will give you the results you want!
I was simply recommending to try networks other networks such as Adbrite, TextLinkAds, etc... Not sure what you mean..
Have you tried stumbleupon advertising? If so what kind of site did you promote and what were your results? Thanks!