is there a easy way to add about 150 items to promotion? I only know manual way of doing it, and if i do this manually it would take me awhile to do it. I can create a search, but I don't know if they have uniformity, I will need to confirm with them. but promotion is not CSV or web service supported correct?

Well then how will you take those 150 times in the first place ? You have the name or internal id of those items. You can create a formula numeric and do something like if internalid IN () Pass in the array of a bunch of statements in the search filter. There will be something for which you need to do promo. Just try to figure out what is that comman end point. Also it's easier to maintain a saved search rather than a multi select field with 100+ options.

Create a saved search is the way to go