[smileysteve]

Yes, your neighbor effects the count. Every card dealt does. Though the more hands on the table, the more knowledge you gain each hand; and this can directly impact a decision to double (though doubling also moves the long game odds towards the house).

An individual can also play multiple hands at the same table (or virtually) to gain this knowledge advantage, though it quickly becomes more obvious.

It terms of etiquette, it's fine to be obvious about counting a single deal, it's the long game that gets you the most advantage and kicked out.