I didn't mean to imply a single factor. The ad spending may be the lighter fluid and the match, but community referrals are the fuel. They did a good job with

I didn't mean to imply a single factor. The ad spending may be the lighter fluid and the match, but community referrals are the fuel. They did a good job with that part. I've never seen an ad from them and I refer them to hundreds of thousands of language learners.