Some problems:
1) You're aiming this at a very Labour/LD heavy board
2) You missed out on all of the more minor parties and nationalist parties, and they get a pretty big share of the vote, especially the Greens, SNP and Plaid Cymru
3) You're asking people who obviously use the internet a lot of they were exposed to a lot of ad campaigns online.
Anyway, it's your study, not mine.