What is the ruling on profiting from internet advertisements, and what are the conditions for its permissibility?

Online advertisements and others are a form of ijarah (leasing/hiring) and fall into two categories:

1. If the advertisements are for permissible things, and the advertisement itself does not contain any Sharia violation, and the ijarah contract is free from Sharia violations such as jahalah (ambiguity) and gharar (excessive uncertainty), then there is no harm in these advertisements.

2. If the advertisements are for forbidden things, or assist in what is forbidden, or if the advertisement itself contains a Sharia violation, such as impermissible images of women or music, or if the ijarah contract contains a Sharia violation such as jahalah or gharar, then the advertisement is forbidden.