Search Engine Optimization (SEO) is the art of getting a better ranking for your web site when people search for it on the web. Of course, as we all know, when it comes to search, mostly you just care about your Google ranking.
Firstly, it is a bit sad to see the money being poured into SEO. When you think about it, the bottom line is that there is a whole industry built up around behind tricking the search engines not to give you the most useful results.
Some of that distortion is fine and legitimate. I mean, if you want to buy a stapler, and the stapler sellers are all investing on SEO so you buy staplers from them, that makes sense. But if you want to find out what a stapler does, then you aren't going to get particularly good results, with the exception of Wikipedia. Unfortunately, the fact that Wikipedia is going to end up being the only authoritative souce on (any idea/item) is another distortion of reality. If you are the world's absolute smartest stapler expert, and you have a web site devoted to staples, but you don't have an SEO budget, I'm afraid you probably won't end up with good ranking in the search engines and you had better get yourself listed in Wikipedia.
Back to topic: I accidentally found a good shortcut to doing SEO optimization. Just do a GoogleAds campaign. I did one for a couple of grand, but I would guess that even a couple of hundred would do. Google apparently knows where its bread and butter come from, so if you are running a GoogleAds campaign on your site, you can be sure to get better ranking for that product on regular Google search too. The best part is that it works not only for the product you are promoting; I found I got higher ranking for all my products for the appropriate keywords. Obviously, the keywords had to be in the text of the pages of my site.
BTW, the GoogleAds campaign sucked. There were too many fake content and link sites, proxies, etc. Most of what I got was garbage, and although Google has been polite and responsive about it, all indications are that they aren't willing to take financial responsibility for spoof site results. I ended the campaign quite quickly.
Although I didn't get one useful lead from the GoogleAds campaign itself, I did get quite a number of other leads, both for the target product and others, by improving my search engine rank as a side effect of the GoogleAds campaign.
So if you are running a site on a low budget, I would suggest trying a GoogleAds campaign for improving your Search Engine results. It is a tenth or less of the price of good SEO, and the results seem to be very good. Even on a corporate budget, I am considering replacing my SEO budget with half as much for GoogleAds. I wouldn't be surprised if I get even better results than traditional SEO.