Oddjob, here is my response to your questions:
In general, normal sedo accounts don't seem to get much from parking. They were the first place I tried and it didn't get me much. Of course, my domains were not very good either and that is a huge factor with parking.
You need to have either lots of traffic, or have keywords that command high bid prices, or (oh happy days) both. In my early days, I didn't consider either one much, but now I focus on the high bid amounts and try to find domains with at least some traffic. If I only get one click a month for one dollar, I am making a profit. I want to AT LEST break even during the year.
I don't think anyone can tell you how much traffic you "should" be getting, since it's going to vary so much. So I would focus on what you are getting and make sure your domain is making and not losing money. Unless, of course it has a sales value that will be increasing. If not, sell or dump it.
For metrics you have to realize that the numbers are only "estimates" and may or may not relate to your domain name. Alexa scores are "rankings" not actual traffic numbers and I don't trust their page views as being meaningful. I would only used them in a very general way. I hear the Yahoo data is now getting very old and is not being updated. And Google gives you a good indication, but not actual numbers. So to me the tools can be useful, but they are somewhat poor.
I go after keyword phrase domains. Yesterday I hand regged annuityfund.org & annuityfund.info. I generally look in Yahoo/Overture to find phrases with traffic, then check Google for ones with high bid prices. Then I see if any of them are available. Most of the time it's only the trash TLDs like .info, .biz, and .us. Other times I can get .net and .org. If the domain is really hot and they are all taken, I will check the domain with hyphens. Often I can find a .com that way. Now you will hear almost everyone trash-talk these domains with non-.com and hyphens, but my best revenue domain that I have parked is a 3-word, 2 hyphen .info domain. They may not all do that well, but the fact that they CAN should encourage people to try them.
[Disclaimer: out of 483 domains in my parking account, only 46 made a dollar or more last month. And my total income was only about $200. So if my domain registrations are costing me about $4,000 a year, I am only making about $1,200 at this point. Clearly this is not a good business yet and I need to do more work at optimizing my pages and dumping domains that are not and will not make any money.]
And lastly, just because typos or anything else is searched for it doesn't mean that people are going to do a direct search for it with a .com. I don't have any numbers for you, but I suspect the search numbers have to be pretty high before you will see much to your domains...
