Yes, Gil is correct. Spam bots are always scanning sites for e-mail addresses. By typing out the email address normally (
person@isp.com), the spam bot can get your e-mail address and send massive spam to it (if you've ever been in a situation where you never got spam but then suddenly started getting it after posting your e-mail address somehwere on the web, this is probably why). And as Gil said, by posting it as I did human beings can still figure it out, but the spambots cannot.