I use ADI quite a bit. Having the online store is huge, especially when it shows my day to day pricing. If I have an order over a couple items, I just call or email my rep, have them ship everything to branch closest to me, then have them ship the entire order at once under one shipping charge. It's something that I have to ask for each time, but they don't seem to have a problem doing it.
The reason as it was explained to me was they work to ship items as quickly as possible. That means if I purchase items that come from multiple locations dependent on stock, they drop ship everything because it's faster. On one hand I agree and take that into account when I purchase, but mostly, I'm purchasing a month in advance so an extra few days for a lower ship charge is almost always preferred.
While I was pretty annoyed over the multiple ship charges after realizing it initially, I've found many distributors do this. If I was to make a few suggestions, I would ask:
1. Show the total shipping charge (or at least an estimate) on the quote before purchase.
2. Provide the ability to add my UPS account. This may be possible, I haven't checked; just referencing one of the replies above. If it is possible, well it's still a suggestion to keep us informed.
3. Take a lesson from Amazon. I've noticed lately I have many items shipping together I made on multiple orders. When you think about the logistics there, that's pretty amazing, but I suppose they have to come up with something when they charge $100/year for all the 2 day shipping you need.
To me, making the purchase easy is priority #1. I like my outside sales guy for Anixter as he's engaged and I would like to buy more from him, but ordering from them is such a pain. ADI does a pretty good job based on their online store and my rockstar inside sales guy. The shipping is the biggest area they can improve on; as I summarize, it mostly comes down to just informing the customer.