People feel entitled to support because there's no financial outlay, it's "free". Also, "it'll just take a minute".
The ideal situation is to do the work and negotiate their help in return. "Be glad to help! And you can do $X for me sometime!" Cool thing about that is soliciting help paradoxically makes people like you more. Do the job, then ask them for help. And follow up on that ask or you will be taken advantage of!
Related:
“He that has once done you a kindness will be more ready to do you another, than he whom you yourself have obliged”.
The Benjamin Franklin effect is the brain's effort to resolve the cognitive dissonance we experience when we do a favor for someone we don't particularly like. In order to rationalize our behaviour, we convince ourselves that we must like the person otherwise we would never have done them the favor.
Not 100% agreed with that last quote as it works for people you actually like. But that's the general idea.