I avoid saes people on the street, but not in department stores, as they are genuinely there to help you rather than just trying to get you to buy something. Yesterday I was in a shop, and asked if I wanted a closer look at anything behind a cabinet, and I liked that because I wouldn't have asked otherwise.
You can usually gauge whether the shop assistants are the kind that harass you when you are trying to look around- especially in say Harvey Norman and other electrical shops where the staff members are fighting for a commission. That's who I tend to avoid!
It annoys me when they chase me around the shop asking if I need help. If I needed help I would come to them. I will usally walk out of a shop if more than one salesperson comes up to me and I'm happy to take my business elsewhere.
I can never find one to avoid. I realise in places like Target, K Mart etc. that they are not MEANT to be required because everything has it's price etc. on it, but that isn't always the case when I am shopping. But in other stores, when sales people approach, I always try to explain that I am just looking and have no intention of buying. I also realise that they don't approach me out of choice, that they are usually instructed to do so and there is probably a manager sitting out the back watching them. My sympathy always lies with the worker, never the boss.
Yes, I don't like sales assistants that HIDE but I certainly don't want assistance until I ask for it. However, there are many shop owners/managers that cannot bear to have the sales assistant being visible and available. They have to have them bothering customers (which puts most customers off making a purchase) Owners/managers seem to feel that if the sales assistant isn't moving all the time that they aren't getting enough bang for their buck. It is a lot of fun if the manager is on site, to approach them and ask them to "call off" the sales assistant. It is not like the sales assistant want to be bothered asking you if you need assistance. People should think things through before canning sales assistants and checkout chicks (well any person that has had a job in the life anyway).
The stores' I frequent, I'm usually known by 'name' if not by 'sight'. It's been like this for decades. They know I will approach them IF I'm definitely going to buy an item. Otherwise they just leave me alone to 'browse'. Works well for both parties'!