I've recently come upon a thought: I have 65 sites on my count of visited whs but only 27 tentative sites I visited. I was wondering whether others find themselves in a similar situation.
If you do have such a significant difference between the two figures in favour of the first - what do you think might cause this deviation? There are far more tentative sites than ones enlisted - so one could expect both lists to be equally long.
Is it perhaps because the sites already on the list are the most famous ones? or more significant than the multitude of sites still on the waiting list?

In my case it is the same: I have 177 WHS and 96 TLS. But this is mainly due to the fact that when I began travelling around European WHS, TL was unavailable on Internet and I have done some big travels without being aware of and visiting TLS (e.g. southern and central France). There is also the fact that some TL contain some unclear, unidentifiable or even mysterious sites (e.g. Spain's or Netherlands'). The value of TLS is variable, there are some sites more worthy to be inscribed than some of those which are already inscribed (eg. Italy - Palermo, Cappella degli Scrovegni, Certosa di Pavia and many others; Belgium - Gand; France - Carnac;...) and some not (e.g. again see some of the Netherland's or Spain's sites): so this is not a fundamental factor in this question.

Furthermore, T-list sites are not usually major tourist attraction and can be down right "way, way off the beaten path". Thus, one is more likely to visit WHS unless one is actually trying to visit sites on the T-list. I do second the thought that the lack of information on the T-list sites is also an important factor in the difference in visiting number. Finally, some T-list sites (Grand Pre) don't want attention and actively discourage tourists. On the other hand, if your on the WH list, then you probably like tourists.