I am wondering if it is better to have 1 add block or 2? someone told me if you have just 1 add block you get a higher amount for each click you get.. plus the fewer add blocks the less cluttered your site looks. whats the general opinion on this?
It depends on the payouts. If you are getting high value ads, then adding another block could help your profits as it probably means there are plenty of advertisers willing to pay more.
It's really niche (and language) dependent. So test, optimize, and test again till you know what works for you.
I use to believe that CTR played a role in click payout. I have been using YPN for a while now and got back into the adsense game so re testing is very important to establish whether or not CTR does pay a role at this time. I know when I was heavy into adsense las year, that low CTR seemed to pay out less.
Displaying fewer ad blocks will mean that the clicks (usually) will payout higher. This means that only the higher bids will be shown, instead of a range of ads, including the low paying ones.
In theory, the fewr the ads the higer the value of those ads, but the having to few ads might result in fewer clicks.
This is an area where, unfortunately, testing is the only way to find out what works for your site. Depending on your niche you might not have a problem with having multiple ad blocks, seeing as they should all pay the same amount (more or less). However if there are few advertisers for your niche then you will get lots of defaults and much lower paying ads in the secondary ad blocks. You need to find a balance with the payout amount and the number of ads you show to the visitors to select from. A larger choice means a larger chance of something catching a visitors interest.