I've said it before. Don't try buying or advertising it. You have to let it develop on it's own. It feels so much more natural and is MUCH more rewarding to both you and your character if you just write what you want to write, what you feel and what you need to write and when another character arises and shows interest, explore that if you like the attention your character is getting.
I've seen more than once where someone has advertised to get family members and convinced others to create characters for a relationship and it rarely ever works out well. Either the writer they get stops writing and loses interest or the characters grow and develop, which they will and should do uniquely and apart from one another, and they become two very different characters that just don't work. That, or you end up getting someone who already has a character and they end up not working out because you attempted to arrange it and again it feels unnatural.
If you really think about it, you need to treat your characters relationship like a real relationship. Sure, someone might find the love of their life on some internet site, but all the factors that applied to them do not apply to yours and someone else's fictional characters who didn't fill out a bunch of information in order for someone to arrange something with someone else based on compatibility. Let it be natural. Just wait till it happens as a result of your story.
For the record, I'm single IRL and refuse to use an internet site to meet women. It was just an example.
