OK ..............
How about having a Weekly / Monthly ( though I think weekly would be better..... more instant ) clicking competition ..........
Who ever clicks-threw to the most sites in the period gets a prize ... 25 free moves / 1000 MD's ..... Probably graded the highest 1 - 10th ( gives a bit of extra competition ..... and if we wern't competitors we wouldn''t be here)
You could either have all the 'Clickable' sites in a list or randomly spread throughout the site.
A 'Leader Board' might be a could idea to give players an extra incentive to get onto it ( a picture / list is worth a thousand words ) . If two or more players are on the same number of clicks the one who clicked first is on top.
Benefits
1) Additional revenue to the site.
2) 'Free Players' , after they have used up there 250 moves have another way of getting MD's / Moves AND generate additional revenue you wouldn't normally get.
Downside
1) Depending when you start / reset the clock for each period, international player may be at a disadvantage.
If you need an idea how this could work take a look at
http://archerfish.co.uk/pages/index.php?refid=mgoodyIf you join then look at the 'Top Clicker Contest' you'll see what I mean. ( and this isn't a 'Plug' for me ..... you can de-register as soon as you've had a look )
Hope this gives you another set of ideas.
Have Fun
Mick