Going over my Facebook page, I see I can create an ad with an estimate of the number of Likes I will receive for money money. $5 per day suggests between 5 and 19 Likes, with similar multiples per budget.
Has anyone used this, and did it pay off? It seems a fun thing to try, $1800 per year works out around £1200 for an estimate of between 1825 Likes to 6900 Likes.