Most of the PAYG networks now make you top-up around £10-15 per month, either a direct debit type or just walk into a shop and pay it, but the credit of data only lasts a month and doesnt roll over to the next month, so say you buy 10gb's worth of data then you have 30 days to use it then its gone... back in the day(normally a wednesday) they didnt do this, it was buy and use till it runs out... then they thought hang on we arnt generating a steam of income here, so they made it 30days, thats why most of the companys payg dongles you still have to sign up for a direct debit, but can cancel anytime...
And the different networks just because some data networks have better coverage than others, three have the best data network with good speeds, but they are the newest, others offer better reception, really depends on your areas, but with the mifi boxes you have different profiles you select depending what sim you have... its kinda failsafe....
ebay 'data sim no expiry'
And as far as the iphone, get one, or andriod phones, the more you know about the phones the better, always a good conversation subject whilst sitting in a customers house waiting for things to download, also increases time there and makes you money...
You could start drinking tea or coffee with no milk so it takes longer to cool down, and if they ask do you want food always say yes, saves buying on the way home... then you've made your money back on the sims....
