Great start in conversation. Yes, conversion in sales and opt-ins. For me conversion increases when you back in the right product offer and like you said "common denominators". Lots of pieces there to getting it right.
Bhupinder, great question. Working on some very specific targeting for a financial service is key. Finding your niche is an important step. There is a lot more, but definitely need to get that part right. As for book, self publishing how-to books need to find use key words and number of other things to find the best audience, etc.