Originally Posted by
FatnLoud
Not wholly correct.
I did this a couple of years ago. I was working for the US subsidiary of a UK company. I managed a project (coincidentally not far from Sacramento) and spent 80-odd days in the US under VWP and then spent a week in the UK, I then went back for about 60 days. I've been back to the US since and not had a problem.
I checked with the US embassy in London and this is permitted, as long as you are not an employee of the US organisation.
Networking and business development sounds like looking for work - that is not allowed.
In terms of "resetting", there are restrictions on what constitutes leaving the US. Simply going to Canada or Mexico is not allowed and I believe neither are some Caribbean countries, not sure about Costa Rica.
OK, but your described situation really only applies to very few people. In all the other cases it is considered work, and that will get you denied entry.
Simply put, you may have actually been lucky. If the immigration officer you encountered was a little less versed in the rules, or just stricter, you could also have been denied entry and you would not have been able to appeal that decision.