Tirupati is the most visited temple in the world and the wealthiest, and both facts follow from an unusual arrangement: it is administered by a statutory public body rather than by a priesthood.
The scale
Roughly twenty-four million pilgrims a year, about sixty thousand on an ordinary day, over a hundred thousand at festivals. Pilgrims queue in caged corridors for many hours, and the darshan itself lasts a few seconds. The temple's laddu prasadam is produced by the hundreds of thousands daily and carries a geographical indication.
Where the money comes from
Two streams, and the second is the strange one.
The hundi, the donation vessel, takes cash, gold and jewellery from pilgrims, running to a very large annual figure. And tonsure: pilgrims shave their heads as an offering, in numbers running to tens of thousands a day, and the temple auctions the hair to the international wig and hair-extension trade. A devotional act of self-abnegation is the front end of a global commodity chain, and the proceeds fund hospitals, schools and universities.
The administration
Tirumala Tirupati Devasthanams was created by statute in the 1930s and reconstituted under later Andhra Pradesh endowments legislation. Its board is appointed by the state government.
That legislation also abolished hereditary priestly rights. The priesthood became an appointment rather than an inheritance. Whatever one thinks of it, the change is fundamental: an institution that had been the property of particular families became an arm of state administration, and would be unrecognisable to anyone who knew it in the nineteenth century.
The declaration
Non-Hindus are not barred, but must sign a declaration of faith in the presiding deity before entering. Given statutory footing by amendment in 2006, it is law rather than custom.
It is a meaningfully different rule from the flat exclusions at Puri and Guruvayur, and the difference is instructive. Puri asks what are you; Tirupati asks what do you profess. One is a status the visitor cannot change at the gate. The other is a statement the visitor can choose to make or decline to make, which has been criticised both as a meaningless formality and as coercing a declaration of belief as the price of entry.