I’ve got to disagree with those saying don’t spend something like $40 a month initially… 6 months is a long time to wait for free search engine traffic, you may as well try something to kick start you early – even if it is a bit of hit and miss (depends on your circumstances of course – if you can’t afford to invest $100 or so over a couple of months for possibly no return, then free traffic is all you’re going to try for anyway.)
I definitely agree though about not wasting your money on traffic merchants that offer x,000 hits for $x – that’s just a total waste as the traffic is highly untargeted (despite their claims – they obviously have a different definition for targeted traffic than I do) – just think about it like this… these sites give you traffic from pop-up (or pop-under) ads from other sites…. how many popups do you typically leave open and properly check out a site when you’re surfing? compare this to how many sites you properly check out when you click on a link from a search engine after you’ve done a search? absolutely no comparisson is there?
I launched my site two months ago (http://www.bonustracker.com), the first couple of weeks I stuffed around trying free traffic exchanges, things like that… next to useless unless you already have some decent traffic (and even then it’s debatable). Since then, I’ve spent about $150 on PPC advertising (and if I started over, I’d probably only spend about half of that for similar returns)
So what are the results? Yes, I only have a dozen or so real players, and I’ve been lucky enough to land a couple of whales in that bunch too, but $300 in commissions the first month, and just hit $1000 in commissions for the second… seems like a pretty good return – admitedly, the majority of those commissions appear to only be from 3 players – but any one of those three would have covered my advertising costs.
I guess it’s up to personal preference, I know I’ve been lucky – although I think you have to target the right keywords etc. to give yourself a chance, and for these first two months I feel as though I did that… this next month will be a bit of a test, as I’ve just started bidding on what I would class money drainers (no deposit type keywords), but I can’t resist – I want to see how that goes giving some NDB’s pretty good coverage. I’m not paying anywhere near as much per click on this traffic than for the better keywords – so it will be an interesting exercise I think, although I wouldn’t be suprised if I pull it after a couple of weeks 
I think if I had to wait 6 months to get my first check, I’d probably give up on it before then… PPC really kickstarts things until your free SE traffic starts kicking in. I’ve been studying up on SEO for the last few weeks, and starting to implement those kind of things in my site, but high traffic keywords are pretty competitive and I think I’ll need every one of those first 6 months to start seeing decent results… until then, I’m very happy to keep going with PPC advertising.
Hope that gives some newbies some heart, you can get decent results pretty quickly, but like I said – if you can’t afford to invest $100 with possibly no return, you have very little option but to rely on free traffic measures, and I really can’t see that netting you too much for at least the first few months… if you can afford it, then it’s worth giving a go (IMHO).