So booking in advance definitely seems to have benefits.. An example below for Paris pass
Discover the joy of sightseeing with the Paris Pass, which gives you free entry to the best attractions Paris has to offer. Save time as you skip the queues with fast track entry at many attractions, including the Louvre and Muse d'Orsay, and take advantage of special offers at various Paris restaurants and shops.
Save time as you skip the long queues, and save money with free entry to over 60 Paris sights and attractions. With your Paris Pass, there is no need to use cash, simply show your pass for fast entry. Choose from a two, four or six day pass.
Paris Pass includes:
A free map of Paris
Hop-on hop-off tour (Two days until 31 March 2014, one day from 1 April 2014)
Free entry to over 60 sights and attractions
Additional special offers and benefits at selected restaurants and shops
Free use of public transport within Paris Zones 1 - 3 (Metro and public buses) for the validity of your pass
Skip the queues with fast-track entry at many of the major sights, including the Louvre, Pantheon, Arc de Triomphe, Muse d'Orsay, Centre Pompidou and many more!