I suppose it depends on the pact at hand. Some pacts are just minor business deals, others are far more long term and require more dedication. I have a few pacts that require different dedications, some one off and some long-term, but at the same time they are specifically for incredible gifts. But of course not everything I do is a pact, I enjoy and prefer doing magic on my own or asking for spiritual aid, and personally consider a pact a very serious and important deal.
With blood, it’s definitely not the only way to show how serious you are with a pact or even spellwork, and not everyone is able to give let alone be able to safely prick themselves. Different practices practice differently. Not all spirits want or need blood, let alone that safely giving blood may not be an option for some people, and some spirits love to receive blood (or other means of life and fluid). I’ve given blood a couple times but I have to be careful because I’m anemic. Other than excessive bleeding it can cause painful bruises on me and I’m more susceptible to infections and illness. Otherwise, I prefer doing work, taking time to dedicate something to the entity, making gifts, giving food, and more. So, of course blood isn’t the end all be all ingredient for spellcasting or pact making. Sometimes it’s dedicated work, sometimes it’s a one off sacrifice, it really depends on the individual, the work, and the entity. I wholeheartedly agree that offerings can be anything, especially time. Time and dedication I think should be utilized more often. Especially as for some people who are extremely poor, not everyone has the ability to sacrifice or offer things above and beyond. Sometimes a burger or a sandwich is all they have, or dedicating their time and efforts into performing work in the name of their entity or spirit.
Personally, I don’t like the implication that food, especially simple food is not a viable offering here. It’s not unimportant or lesser, and it’s unfair to those who are either poor or don’t have other options and therefore genuinely sacrificing something of themselves, or it’s just discounting the work and dedication it takes to cook and prepare, or outright throwing away or ignoring traditions of many cultures that utilize simplicity. To my local spirits we’re supposed to offer simple things. A bag of lentils, a pack of cigarettes, a bowl of rice, a cup of hot chocolate, a bottle of tequila, etc. Simple offerings have been used in many cultures for generations. They shouldn’t be excluded just because they don’t have the same edgy fanfare.
Time and attention is definitely something to utilize more, but also not all spirits give a shit about the individual’s ascension or betterment, either. Some demons and entities just want renown and reward, even if the things they want don’t make sense to human standards. I’ve drawn portraits of demons for them in exchange for their aid before, among other instances of renown and putting their name out. I also think people should learn they can negotiate, too. What a demons asks of you doesn’t have to be the Absolute Only Thing you give, you can offer or negotiate alternatives.
Overall, some spirits want blood, some want food, some want just shiny treasures. It really depends on who you work with and what your capable of giving, plus you can always negotiate.
Also to touch on Eliphas’ response: Paradise Lost and Dante’s Inferno aren’t necessarily “fanfiction.” Milton invokes the spirit of Uranus in order to help him tell the story, as she is the spirit of the Heavens and is meant to have all knowledge of the Heavens and its creation, much of both of these works are historically and religiously important especially because they wrote down a lot of common knowledge (as well as personal interpretation of course) that is not necessarily “canon” but simply widely known and believed by the populace, such as in Books I and II of Paradise Lost, Milton lists several demons being worshiped as gods, comments on King Solomon’s dealings with demons, as well as establishes what some of these demons’ offerings or oversights. Discounting Paradise Lost as just fanfiction is basically the same as discounting all non-Torah rabbinic or non-Jewish (biblical) texts and magic grimoires as fanfiction due to their reliance on either common folk knowledge or spirits that were called upon to aid the writer. Lilith isn’t in the Bible, and her story is in the technically non-canonical Alphabet of Ben Sira, that doesn’t mean that she doesn’t exist as a demon. Not believing in these works is one thing, or taking them metaphorically or with a grain of salt, but to insist they’re fiction because they’re not Official Canon is narrow.
Sorry for the length, I just love history and cultural difference.