A huge bar of Cadburys chocolate got us a room upgrade at the Holiday Village in Sharm a couple of years ago
Sea view, a kids den and a bath as well as a shower.
The chocolate has also got us late check out rooms in Turkey.

Sometimes Shirley I think it is just luck of the draw

A friend of ours had to fly out to India last year and he got picked for an up-grade to First Class just like that

Only time we got an upgrade was a couple of years ago. We were on a Coach Tour and when booking had requested a room near the lift. I also emailed the hotel a few days before arriving to re-iterate our request and explain my husband could not walk far. On checking in, My husband sat in reception while I went to the room to open windows (his problem is more breathing difficulties than a problem with his legs) Anyway the room could not have been further away from the lifts. I was struggling myself. Back down to reception and was told no other room available but another girl in reception spoke to the one dealing with me and we got the keys to a Superior Room near the lift. Apart from the extras in the room, we had a beautiful view over the harbour, two comfy armchairs and coffee table where we could sit and watch all the coming and goings.
I know that this was not the usual upgrade but as my husband wasn't too well when we were there, it was great to have a view. None of the Coach Companies offer the option of a Superior room but if we are able to go again I will email or phone the Hotel to pay the difference as although we got it free it would have been well worth the difference

We did ! We'd booked a standard room with thomas cook for our holiday in mexico last year, but had been in touch with the hotel via e-mail about renewing our wedding vows ( our 10th wedding anniversary whilst there ) so we arrived and the lady on reception said 'we have upgraded you to select rooms and have a surprise for you ' so we jumped on the golf cart, got to the room, a massive upgrade from what we had booked and they'd decorated the room with balloons, flowers, we had a bottle of champagne on ice, t- shirts with 'just married' on, chocolates, bathrobes, slippers, loads of gifts on the bed, I have to say, I cried ! bless 'em ! truly fantastic start to a wonderful holiday, and 8 days into the holiday, we renewed our vows on the beach and when we got back to our room, they'd decorated it all again with everything , plus loads more champagne and chocs !!! result !!

We were given a free sea view room if you can call that a upgrade when we visited Tunisia in 2009 , because of our original hotel booking was going through some renovations and some of the facilities would not be open to us , we were given the option of either changing hotel , cancelling the whole holiday without loss aff any monies or rebooking a different country

our best was 3 nights in the owners own suite [huge round bed with satin sheets, and a full gym Axminster carpet and top quality fixtures and fittings] room as the hotel had made a mistake and cancelled our rooms in error .. he went home to mother for 3 nights

Had a few. Booked direct with a hotel in Ko Lanta, got there and they upgraded us two room types to a deluxe villa with glorious views over the pool and Andaman sea. Used to get free upgrades all the time in South East Asia hotel

Booked a room on the day of travel at a B & B in Laugharne South Wales. Got a call back a few minutes later saying they were double booked and they had put us in a nearby hotel which turned out to be a high grade boutique hotel with many of the guests arriving by helicopter. A result, except we had not brought the clothes with us for staying at a posh place as we were on a walking weekend.

I'm a Platinum member with Holiday Inn so automatically get room upgrades at Holiday Inns/Crowne Plaza and Intercontinental hotels which is quite useful - fat lot of use if I stay at a Holiday Inn Express though, as all the rooms are pretty much the same.

We booked a weekend in the Lake District for the in-laws a couple of years ago for their 40th anniversary. We didn't tell them where they were going until the week before and hubby phoned the hotel a few days before to arrange for flowers and champagne in the room as it was their anniversary. When they arrived the hotel had upgraded them because it was their anniversary and we kept getting texts from them (we were on holiday) telling us how wonderful the upgrade was, although it looked a fabulous hotel anyway.

Had a free upgrade from a one bedroomed apartment to a two bedroomed two floored apartment once in the Algarve. It was Fab. I had checked the price at the time of booking and the free upgrade was worth at least £500 as it was a fortnights holiday. Whoopee !

In Sharm booked two twin rooms, was given a king sized room with massive 7ft bed, then a lounge/kitchen dinner in between and then the twin room for my teens, all connecting to each other. It was a family suite and was more a lot more than I had paid.

So we had three outdoor terraces, three TV's, two Bathrooms, massive fridge freeze, kitchen with marble worktops etc It was the business. Yeah !

Booked a villa with pool with Cosmos and was informed it was double booked so they upgraded us to a different one that was larger/more expensive.

My parents booked 14nights to The Maldives a few years ago. It was a 3 star hotel, all inclusive, no swimming pool but was beach front.

They received a phone call a few weeks before they were due depart to say that couldn't stay in the chosen hotel, but had somewhere else for them.

It was a nice 5star hotel, all inclusive, with a swimming pool! Lucky people

Got an upgrade at the Holiday Inn Glasgow Airport when we were so late checking in that they'd given our rooms away. Ended up with wine, chocolates, bathrobes etc for both rooms.
Also got one in Las Vegas when we complained that the room we were checking into hadn't been hoovered. It had bits of chinese food all over the carpet - yukk!

We unexpectantly were given a suite when we arrived at our hotel in Tunisia. No idea why !

I had a free upgrade when I went to a Champney's health spa resort a few years ago. We had originally booked for their resort in Wiltshire but as it was being renovated we were moved to Henlow at the last minute which is much further to travel. Can't complain though because our room was gorgeous and would have cost us a hell of a lot more money if we'd have paid for the better accommodation.

Not an upgrade as such. A few years ago we had 2 rooms booked at the Durham Marriott for an inter counties athletics meet at Gateshead. When we got to the hotel they told us they were over booked and we had been given two rooms in a castle, can't remember it's name.
We checked in there and hated it. Neither of the 2 lads (athletes) we had with us wanted to stay, so I rung the Durham Marriott and they managed to get two rooms at the Sunderland Marriott. What a result. We had huge seaview room and the lads got a great twin. The bonus was it was the Sunderland air show and the rooms were mega expensive (hence we hadn't booked there in the first place).
Even better, because of the overbooking, they didn't charge us at all. I do like freebies

I think it depends on a combination of factors, one of the main ones being time of year. I was in Mexico last September which is a quiet time of the year really and was upgraded to a junior suite deluxe (from a junior suite) as the hotel was quiet. Most First Choice / Thomson guests had been upgraded due to the low occupancy. I've been upgraded a couple of times previously as well, it's luck of the draw realy. Go in a busy period and it's unlikely you'll get a free upgrade. As has been mentioned, sweetners help as does return visits if they know who you are or having a privillige card for the hotel chain you're staying at (always worth joining them for that).

Darren

We got a free hotel upgrade when we went to Slovenia. We had booked the 3 star Marita but they decided to close it for refurbishment just before we went so we were moved to the 5 star Grand Hotel instead which had a much better location and facilities. We were dead chuffed!