tedster - 6:32 am on Oct 10, 2006 (gmt 0)

Roll them out one at a time, each one with a very focused topic and the all the caveats above apply. Your client will need to come up with 50 different and discrete topics and the means to develop and maintain/refresh the content in an ongoing manner. You will also need diverse means to establish authority and trust for each domain, not the same promotional "footprint" for each one.

You can cross-link in moderation, but it's not going to do much good until the "weight" of each domain gets rolling. It's a big-old job, and not to be taken on lightly, least you jeopardize the core domain. The days of easy index spamming and promotion through sheer numbers of backlinks are no longer with us.