I`ve created a website to help create leads for my brothers training business and he gives me commission on any converting leads which come from my site. On my site I have a question form for people to ask about training, prices, e.t.c and I store them in mysql. I have created a simple admin panel for him to go through the questions and answer them and send them to his site for training booking. He has a website that processes payments and it works fine but, it`s old, form based and we have no idea how to setup tracking. So we have just been going through my sites names, emails (200 and growing) each month and looking to see if any are on his Access database customer list(5600). This is not perfect as some will add different info on my site to when they order and we won`t find all of them but, I`m not too worried about this as I`m still helping my brother out. As you could imagine this is very time consuming and is only going to get worse as my leads list is getting larger by the day. He is currently getting a new site built and we plan on adding some kind of tracking system but, that's a long way off. Is there a way to add each data to separate spreadsheets then compare them for similarities? Or do you know of a better way we can do this? Any input would be great.