Is this accepted?

[kit07]

As for selling service, this is in the grey area, technically you are not looking for party and doing something that SE does not really encourage... You can probably do it but may/may not get nasty tells.

Is there any particular reason why they don't like this sort of thing?

[JustPlainLucas]

Is there any particular reason why they don't like this sort of thing?

Some would call it spamming. I've also seen someone on this board get the definition of advertising mixed up in the Terms of Service, thinking that it also applied to advertising services in-game, but without actually selling services and goods for real life currency. Also, some people don't want to see services in the PF, as they're afraid it will turn into another marketboard, but that has never happened.