I think online advertising is like any advertising, it`s not how much or how big but where and repetitive. I`ve had some good success on a limited budget with online ads, both PPC and placement, but it has been because I`ve been very focused.
My organization is not B2C, but what I would do is think about the forums and see if the people there are decision makers for your product or service. Millions of hits (you want to actually look at unique visitors, not hits or page views to evaluate ad worth) are great, but I`d rather be in front of 10 people who actually may buy my service than 1000 who I have no information on.
If you can ascertain they are your target and the price is right, it`s worth a shot. Nothing risked, nothing gained.
Just continually watch your conversion ratio- don`t spend $3 for a $3 sale, make sure your product offerings are wide enough so that you can make additional sales form ancillary products, and make sure your user experience is painless (if not excellent). At least that`s my 2 cents, from my experience. Hope it helps.
"It`s not work, it`s network!"
Portage Media Solutions
My Blog: http://www.interactivemediatips.com