HORSE MURDERERS!!
tbf you'll still get 5x your stake for a place, so it's not a bad bet IF your mate's info is good. I would suggest that most "tips" are trash, though. Good tips don't get shared around publicly (because that sparks a flurry of bets which alerts traders and drops the price like a stone) - if you want ACTUAL good tips, hang around a counter and listen for what the guys who are handing over money in "bundles" rather than single notes are asking for in whispers then muttering to each other about.
In all my time in a bookies I never got into horse betting - but there were a handful of occasions where the big hitters were getting
tense AF and whispering about random horses and I'd go and stick a fiver on them elsewhere. And then alert our own traders
. Quite a few did indeed win.
ALSO - some more industry factsss - syndicates price-bait. The more bets there are on a horse, the more its price will drop, which pushes the price of others out (e.g. pushing an odds on fav out to evens)... The syndicate then bets heavily on the ACTUAL favourite, whilst the chumps they've leaked a false tip to get nowt