Statistically, most people find their partners through their friends. Thus it seems a good strategy for finding a girlfriend would be expanding your general circle of friends.

If he already doesn't have / never had a girlfriend, it suggests he is not the type of person who could easily do it through friends, perhaps, due to not being very social. Wanting to "use" a GF for all the things people often use friends for is an evidence in this direction too.

I would recommend online dating.

On a more meta note, I think statistics should not be used this way. I mean, simply doing things that most frequently work for others. Sure if it takes ten minutes to try, then why not, but when it is something that takes a lot of time investment and waiting - how long should he try this find a GF through expanding friends thing before giving up, a year? - I would not do so. I think statistics should not be intepreted this way.

My view of statistics is that if you are not already doing the statistical thing, then it is a sign something is different about you and you should try something else.