I suppose for me there are several categories. 1) If other data or significant user input of any sort is required or possible get a log in so that progress can

I suppose for me there are several categories. 1) If other data or significant user input of any sort is required or possible get a log in so that progress can be recovered. Shopping is probably an exception, I don't generally want an account just to buy the thing. 2) If it is a webservice or API or something similar I won't sign up generally until I have seen a) the pricing b) some documentation and c) had the option to review the terms of service. Going back to an earlier post today about improper use of Google's maps API. Don't hide your sales information (and that includes technical documentation) behind a sign in without a good reason. 3) In some cases I understand the the email address and permission to send me further marketing is the price of access to some information. I understand this and if the offer is good enough I may expect although I will probably decline four out of five times.