”Pilgrimage tourism” is an unusual word, at least the way we understand it. Pilgrimage is essentially a pious religious event and the word tourism essentially sounds something commercial. Truth is that these two overlaps or sync together in many aspects.
Pilgrimage is an integral part of the travel plan of many Indians. For example, a devote family who visits the hill station of Kodaikanal in Tamilnadu, in all most all probability, shall include a darshan to Palani temple- the famous abode of Lord Muruga, in their itinerary which is nearby. Case is same with a person who is on a visit to Chennai with Tirupati or Kolkotta with Dakshinewar temple etc…. Thus, pilgrimage and tourism is getting more and more integrated.
It has its side effects too. Foremost is the commercialisation of a thing which is meant to be sacred and highly personal. The Kumbh melas, Rathyatra at Puri Jagannath temple, Kali Puja in Kolkotta, Ganga Aarathi at Varanasi …all are examples of this unhealthy trend.