****1 Month update ****
For anyone who is interested, I thought you may like an update.
I have been putting all my domains into parking, regardless of whether I think they are potentially good for parking or not, just as an experiment.
-I have 129 domains (they were not all added at the same time).
-All of the domains have received at least 1 visit.
-The most visited has 83 visits in the month. Its not one I expected to get any visits as it only has 23 spammy backlinks and its not a keyword. Having said that, google keyword planner does say it gets over 100k searches a month and a bit of further research reveals that it may be a typo for the first name of an Arab singer. More research is needed!
-I have a couple of 'keyword' domains, and there is one that google keyword planner said its average monthly searches are 1k-10k, but this has only gotten 5 visits. I would have expected this type of domains to get more visits.
-Only 6 domains have had clicks on the ads (which is what earns the money!). 2 are surprising as they are not really keyword domains, so no really obvious ads to show.
-17 clicks in total, Earnings per click range between 0c (yes I got $0 for one click!!) and 44c and the grand total for the month is $2.42
I'm enjoying it as an experiment and will continue for a while. I'll report back again if people are interested in the progress.