I no it can depend on a lot of other things but realistically how much daily traffic do you need to make money from Affiliate Programs?
There really isn't an answer to this question. If you could make $10 from every 100 visitors and it was set in stone like that then it'd be easy, but you're right, there are many other factors. It depends on the market you're targeting. It's very possible to make good money from a small market base. One site depends on a market potential of 25 people searching for a keyword a day. Out of that 25 people I expect / get 5-10 people to visit daily. Out of that 5-10 people, approximately 0.5 people buy a day, equally 1 person every two days. The product they purchase ranges from a $28 - $199 dollars netting me between $7 and $50 every 2 days. So, it really depends on your market. If the affiliate scheme you're participating in is for one particular product then I'd say you could make money from about 15+ unique daily visits. Remember, with specific products, people are searching a product name and therefore more likely to be in a 'purchasing' mind frame. If the affiliate program is more generic, then it's like trying to answer 'how long is a piece of string?'.
As much targeted traffic as possible, there is no maximum, keep getting your links out there and push for that targeted traffic.