In certain cases, where a season ticket isn't much less than 5× the walkup Anytime (Day) Return - such as many set by Southeastern, West Midlands Trains etc. - and where the Anytime (Day) Return is above £12, getting 5 Railcard-discounted walk-up tickets each may be cheaper than a season ticket. Obviously you don't get the same flexibility (e.g. being able to use it for more than one return trip a day, or on the weekend) but in certain cases a lot of money can be saved in that way, plus you only pay for those days you travel and there can be no problem of fees for refunds or a high upfront cost.