Setup a Google BLog Alert with the keywords/phrases that relate to your product. Every time someone talks about it,contact that person and tell them what you think of their article (be honest) and shamelessly plugin your application. They expect that and they need the stories.

Affiliate marketing. I can never promote this enough. Sign up for PepperJam, Commission Juntion or Sharesale and pay only when you make a sale. Or pay for sign ups.

If your product may interest businesses, then cold call. Or warm call (email then call). Even if your product is free, you can find a few enterprises that may benefit from using it. Call the top dogs, decision makers and tell them how your "new blog/app" is the ISHT and they oughta to stop working and check it out.

Be agressive. Passively.Luck is a "myth" for most people. If someone says no that means "not right now". Keep pushing every other week.

Repeat. If something works, repeat it. Exhaust it.

Try and try more. There is no set way to market or sell. Try everything you can. The beauty of emails or phone calls is that you can be anything you want and anything the other guy/gal wants. "Be water", Be a chameleon.

EDIT: IF you could be more specific about what you do, you could get better advices from readers.