Earlier this year (around April) I used a price comparison website to find the online travel agent with the best rate on a specific hotel I had to use for a conference trip in early July. The rate I found was good and the TA seemed to be well used with good ratings so I went ahead and booked. I got the confirmation immediately and then minutes later got another email showing me offers on car parking, car rental, excursions, etc. Fine. I realise that this is a part of internet shopping.

The problem is that between then and my trip I got about another 40 emails from the TA and since the trip I've had another 11, all of which referenced my booking number to look like some sort of legitimate message relating to my trip. I hit the Unsubscribe button on one of them but got a scary warning that I might be blocking any booking updates so backed off. Today I finally got round to unsubscribing and blocking this TA. They had a good booking rate but I'd never use them again because I don't want to deal with the crap they send me virtually daily.

Is this common nowadays? I use Expedia and Ebookers quite a bit and get hardly any spam from them. What's the rule and what's the exception?