FAA are not happy with these kind of services, I can't imagine any other authority would accept them as well
FAA warns flight sharing services - AOPA
for those in the hurry, in the article there are three sentences I would like to stress:
“A carrier becomes a common carrier when it ‘holds itself out’ to the public, or to a segment of the public, as willing to furnish transportation within the limits of its facilities to any person who wants it.”
"Although the pilots participating in the AirPooler website have chosen the destination, they are holding out to the public to transport passengers for compensation in the form of a reduction of the operating expenses they would have paid for the flight,"
Furthermore, “not only will the FAA be unhappy if you conduct a commercial operation without an operating certificate, but if you are involved in an accident or an incident, your insurance company might be able to deny coverage for any claims made against your policy”
Personally I think when you try to fly someone you don't know, coming from a web site that offers people to rate their pilots - it will affect your judgement, especially when it comes to go/no-go calls due to weather etc. I smell trouble