Nowadays, there are two main ways in which the publication of international film guides is financed.
The first way in which the publication of international film guides is financed is through advertisement revenues. The most reputable international film guides tend to attract huge numbers of readers. And advertisers are always on the lookout for such numbers: leading to a situation where we often see advertisers paying premium rates, for their adverts to appear on the sidelines of the best international film guides. Often (and quite understandably), the adverts turn out to be for companies in the film industry. That is where a company like Sony Pictures, Time Warner Pictures or 20th Century Fox may be willing to pay top dollar for an advertising spot (or for ‘publicity’) on a leading international film guide, just before a major movie release.
The second way in which the publication of international film guides is financed is through subscriptions. The best international film guides tend to be so good that people (that is, the readers) are willing to pay for them. The amounts of money that the readers pay often end up being enough to finance the publication of the film guides, and to leave some good profits for the publishers. Some of the international film guides are financed entirely through subscriptions (or sales), freeing them from reliance on advertising revenue. That independence from advertisers can often be crucial, because publishers of international film guides who are entirely reliant on publishers often find their editorial independence being compromised, especially when it comes to reviews.