For example, is it really necessary for you to ask them their birthday and other information? Probably not, and this is why when they sign up ask them mailing list only necessary questions. Getting your clients email is easier than you think. Don't give up just because you don't think any one will want to sign up for your newsletter. Instead offer them incentives to join up and watch the customers on your list grow to new heights.
I am one of those optimists who still read reciprocal link emails now and again in the hope that I see a spark of originality. I don't ask much, only a few details such as where do you want the link from (be page specific here or forget it), anchor mailing list text and description. It's not much to ask, is it? Rarely, I get an email where someone has actually visited my site, noted the page to which I should add their link and provided the required details.
Those clever people have a chance of getting a link and get this (whispers and draws you in closer); it isn't always necessary for it to be reciprocal. There, I've said it. I don't always need a link back! If it fits with the site, I sometimes give (gasp) a one-way link! Yes, really. I sometimes link to another site without requiring they link back to me. Makes a person feel all dirty, doesn't it? Like some sort of link-slut.