So what are you really going to do? Attempting to try the seo thing? I mean it's a real pain in the ass to consider doing that as an alternative to ppc when google keeps changing the algorithm making it harder and harder each time for a website to get traffic. I just saw the recent update from Matt Cutts addressing that low quality exact match domains would be penelized on the search engine. Though I don't know exactly when that will start to happen I bet a lot of people are considering to use the panic button if they were solely dependent on their emd's.
So let me get to the point of what I feel is a much better alternative to all of this. My answer is Media Buying! But not just any media buying from large networks unless of course that does not bother you.
What I'm talking about is buying media from smaller sites which would mean you spending less money then you would have been spending on pay per click.
So just how would you go about doing this? Well first you would have to find targeted sites in your niche and you would have to research the demographics of those sites. Then you would need to provide the right offer in place for the right crowd (after doing your research). Since you would be buying media on a cpm basis using more visible banners (like around (300x250) you would then have to calculate how much you should be spending per 1000 impressions based on the price of your offer.
Then when you contact the webmaster you need can negotiate a price to paying for a week or a month something you can't do with google.After that you would set a tracking system in place to track the clicks so in that aspect it is still like ppc but you are paying much less.