I've only been writing at Suite for three weeks, so I am not a good one to judge at this time. In a recent update from the editor, someone had received a $1000 payment for the month- so a decent profit is very possible. TCB might be able to give you better insight into profit results.
The thing is, Suite writing should be looked at as a long-term writing endeavor. The longer you write for them, the more you will see payout. Once you have a good base of articles established, you don't have to "work" nearly as much to be paid. Just ride the wave, so to speak. Initially though, you won't see big numbers rolling in. Further, if you are promoted to a Feature Writer position, you will earn at a faster rate.
AC is more profitable if you are looking for short-term money making.
Having written for both, I strongly prefer Suite. However, many of the reasons that I have a preference for them is not financially related. I think Suite is much more interested in improving the quality of writing their authors produce. The adminstration strives to support and educate their writers. I really don't see that with AC managers. I think Suite engages in better business practice. Because of that, I think Suite may have greater longevity.
Also, I have heard rumors that AC may eventually go out to PV payment only eventually. If that's the case, I want most of my eggs in the Suite basket.
I don't mean to sound negative against AC. It really depends on what the individual writer is looking for as to which company is better suited to their needs. For where I am at currently, that place is primarily Suite.
Oh and as far as promotion - I do onlywire, digg, and stumbleupon. I do no inner-networking at all. Much less time consuming than the inner-networking I was doing at AC. However, as TCB mentioned above, I don't know if promoting is all that necessary if you are writing searchable articles and keywording appropriately. I am not getting significant amount of hits from social bookmarking sites.
