Exactly. I'm afraid I am struggling to believe the posters who are saying this. I don't know anyone in real life who would be happy with it.
I know some people do it, and are Royally taken advantage of by cheeky fuckers, but I know NO-ONE who likes it and is happy with it.
Sadly, there are plenty of shameless, cheeky fuckers who take advantage of people who are kind and a bit gullible. And the 'favours will come around' type comments make me LOL. No. Not from the ones who are the cheeky fuckers. This type NEVER return the favour. Some of them also turn nasty when you STOP said favours too. I have had this happen. Not lifts, but looking after someone else's kid.
A mum on the estate happily farmed her DD (Hannah) off to us 3-4 afternoons/evenings a week (she would come straight from school with my DD, have dinner at ours, and stay til 8pm some nights.) AND she would spend much of the weekend with us. DD and this girl were 10.
Some nights, we had to ask her several times to leave. And we had to take her back, as her mum would never come for her, and we weren't having her walking across a big council estate after dark at 8pm. If something had happened to her, guess who would have got the blame? Not her shitty mum who didn't care where she was half the time. WE would have got the blame for sending her off into the night.
A number of times we took her back and no-one was in. And shocker her mum didn't answer the phone, so we had to take her back home, and then go back again at 9pm or even 10pm. One night Hannah's mum rolled in from the pub and came to ours at 9.45pm, and picked her up in a car she was in! (Got a lift from someone!) No 'thanks for keeping her here' or 'sorry,' or anything. Not a single acknowledgement. Just 'GET HERE HANNAH!'
Next time we picked up DD from school, this girl was ready to come along too. We said 'no sorry Hannah, but we are going out, not home.' Hannah looked confused and was like... 
She said 'well my mum isn't in til 8pm.' We said 'sorry but you need to go home.' She got quite angsty and looked like she was going to cry. I said 'ring your mum and ask where you can go.' Her mum answered her, and Hannah said 'my mum said I need to go to yours as she isn't in til 8pm.' DH took the phone off Hannah, and said 'come and get your child NOW, she is NOT coming home with us, and stop taking the piss and constantly making us look after her.' She slammed the phone down.
We waited. Decided to wait for 15 minutes. If she hadn't come by then we would have taken her back into the school. Came to the school five minutes later, (someone drove her,) and grabbed Hannah and scowled at us. 'Fucking idiots!' she barked.
tl;dr the next few months were hell as she systematically turned all her mates (6 of the school mums who lived nearby,) against me. Not DH, ME. I got the brunt of their hate, and scowling, and bullying. DD was bullied at school as Hannah turned 3 other girls against her. (Daughters of these other mums.) Rocks thrown through our window, paint, and eggs thrown at the door, and a gang of people (8-10 sometimes) just walking by our house (even though it was out of their way,) and standing opposite, just staring in. Started several horrible rumours about me. Other mums who weren't her friends - but still knew her - started avoiding talking to me.
We moved out of the area about 8 months later, and DD went to senior school soon after and didn't see this girl again. (And I didn't see any of the horrible bitchy bullies either.)
But yeah, as I said, some people turn nasty when you when you withdraw favours and stop their cheekyfuckery!