Created this illustration tonight and posted it on my blog:

Not comprehensive, but it should give you a good overall picture. Here are some descriptions with practical advice. I'll be writing a more elaborate blog about this sometime in the future.
1. PPC -- You guys should all understand this. First tier: Adwords, YPN, MSN Adcenter, all high quality sources of traffic. Then there are tons of other that range from good (Adbrite) to horrendous (Looksmart.) In order to turn a profit, revenue from each visit must exceed cost.
Pros: Instant traffic gratification
Cons: Expensive, often difficult to manage
2. Hard Links -- Blogs, Myspace, etc. I divide hard links into two categories: send traffic and don't send it. Getting on the front page of Digg can be great for building backlinks because readers also own blogs and web sites and may link to you. Hard links ultimately are a big help in the organic search listings.
Pros: Instant traffic, more of less; helps with SEO
Cons: Initial traffic may not be very valuable (browsers with ad blindness), requires money, friendship, or an a lot of work building a web page people actually enjoy reading (or get really pissed off at.)
3. Organic Search Engine Traffic -- this is all about search engine optimization. Free traffic means you can do a sloppy job at monetizing and still bank tons of cash.
Pros: FREE
Cons: Tons of work to get it, can takes months or even years.
4. Email -- most web publishers today avoid this. Creating a simple monthly email newsletter can help bring back users again and again from a single initial visit. Bulk spam is the most obvious example but targeted, opt-in CAN SPAM compliant e-mail lists have made many individuals and companies millions upon millions of dollars. This source just can't be left out.
Pros: Access an audience without them actively looking for you or your niche
Cons: Lots of work and/or money involved. Staying CAN SPAM compliant can be tricky, and spam lists may still blacklist you.
Feel free to repost the pic (see blog for html link) along with this post on any web site or blog you run. The linkback as given in the html code is a must.

Not comprehensive, but it should give you a good overall picture. Here are some descriptions with practical advice. I'll be writing a more elaborate blog about this sometime in the future.
1. PPC -- You guys should all understand this. First tier: Adwords, YPN, MSN Adcenter, all high quality sources of traffic. Then there are tons of other that range from good (Adbrite) to horrendous (Looksmart.) In order to turn a profit, revenue from each visit must exceed cost.
Pros: Instant traffic gratification
Cons: Expensive, often difficult to manage
2. Hard Links -- Blogs, Myspace, etc. I divide hard links into two categories: send traffic and don't send it. Getting on the front page of Digg can be great for building backlinks because readers also own blogs and web sites and may link to you. Hard links ultimately are a big help in the organic search listings.
Pros: Instant traffic, more of less; helps with SEO
Cons: Initial traffic may not be very valuable (browsers with ad blindness), requires money, friendship, or an a lot of work building a web page people actually enjoy reading (or get really pissed off at.)
3. Organic Search Engine Traffic -- this is all about search engine optimization. Free traffic means you can do a sloppy job at monetizing and still bank tons of cash.
Pros: FREE
Cons: Tons of work to get it, can takes months or even years.
4. Email -- most web publishers today avoid this. Creating a simple monthly email newsletter can help bring back users again and again from a single initial visit. Bulk spam is the most obvious example but targeted, opt-in CAN SPAM compliant e-mail lists have made many individuals and companies millions upon millions of dollars. This source just can't be left out.
Pros: Access an audience without them actively looking for you or your niche
Cons: Lots of work and/or money involved. Staying CAN SPAM compliant can be tricky, and spam lists may still blacklist you.
Feel free to repost the pic (see blog for html link) along with this post on any web site or blog you run. The linkback as given in the html code is a must.